* [Enhancements]: strictNullCheck and filtering:
* (d3-selection) [Enhancement]: Validated, updated and activated to enforece `strictNullChecks`. `BaseType` updated to include `null`. As a result of this approach, the developer must explicitly include `| null`, if a Selection or a (sub-)selecting method may contain `null` element(s). By the same token, the `node()` method, will return `null` only, if the Selection to which it was applied may contain `null` element(s).
* (d3-selection) [Enhancement]: Added additional signature to `filter(...)` method such that a generic can be used to control the type of the filtered elements, should they be a subset of the unfiltered types.
* (d3-selection) [Enhancement]: Added `Document` to `BaseType` union type.
* (d3-transition) [Enhancement]: Validated, updated and activated to enforece `strictNullChecks`. `BaseType` updated to include `null`. As a result of this approach, the developer must explicitly include `| null`, if a Transition or a (sub-)selecting method may contain `null` element(s). By the same token, the `node()` method, will return `null` only, if the Transition to which it was applied may contain `null` element(s).
* (d3-transition) [Enhancement]: Added additional signature to `filter(...)` method such that a generic can be used to control the type of the filtered elements, should they be a subset of the unfiltered types.
* (d3-selection-multi) [Enhancement]: updated `ValueMap` type use extension of selection/transition `BaseType` as defined above consistent with `strictNullChecks`.
* (d3-selection-multi) [Test Fix]: Updated tests where a Value Function is used to return a ValueMap for each selected item, as the ValueMap must be defined as a mapping object idiomatically, the test was changed to never return `null` as a result of the value function. Instead it returns `{}`, when no updates are required for the currently iterated selected element.
* In general, for all three above modules: Tests have been updated to be more explicit about type-checking inside callback functions. Also, where shortcuts where taken in the shape tests to simply test interface/signature contracts, without necessary variable initialization, mock initializations have been included. This is necessitated by enabling `strictNullChecks`.
* d3-force
* (d3-force) [Enhancement]: Validated, updated and activated to allow for `strictNullChecks`. When using `force(name)` getter on `Simulation`, it is now up to the developer to use the right generic narrowing to exclude `undefined` as a return type, if it is known with certainty that the retrieved force has prevsiously been defined. By default, it may be `undefined` as is the standard API specification.
* (d3-force) [Fix]: The initialize method has been added explicitly to the predefined forces `ForceCollide`, `ForceCenter`, `ForceLink`, `ForceManyBody`, `ForceX` and `ForceY`. This conforms to the implementation of these forces, where it is implemented. Inhertitance from the generic `Force` inaccurately let it appear optional.
* (d3-force) [Chore] Tests added/updated and some linting.
* d3-force ForceLink JSDoc update:
* (d3-force) [Chore] Update JSDoc comment for `id(...)` accessor on `ForceLink`. This is related to the corresponding wording change in the API documentation in follow-up to the changes made to d3-force issue 72.
* d3-zoom strictNullChecks
* (d3-zoom) [Enhancement] Validated, updated and activated for use with `strictNullChecks`. Tests updated.
* d3-brush strictNullChecks
* (d3-brush) [Enhancement] Validate, update and activate for use with `strictNullChecks`. Tests updated.
* d3-drag strictNullChecks
* (d3-drag) [Enhancement]: Validate, update and activate for use with strictNullChecks.
* (d3-zoom) to v1.1.0
* (d3-zoom) [Feature]: Adds suppport for `zoom.interpolate(...)`. Tests added
* (d3-zoom) [Chore]: Updated JSDoc comment for `zoomTransform(...)`
* (d3-transition) JSDoc comment
* (d3-transition) [Chore] Updated JSDoc comment on `selection.transition(...)`
* (d3-transition) [Chore] bumped version to 1.0.3 to indicate up to which module version the definitions were reviewed
* Bump patch versions of underlying modules
* (d3-brush) (d3-drag) (d3-force) [Chore]: To indicate up to which patch version the files definitions were validated, patch version number has been bumped
* TS Lint and Minor Changes:
* (d3-brush) [Chore]: Added tslint.json to disable "unified-signatures" rule
* (d3-drag) [Chore]: Added tslint.json to disable "unified-signatures" rule. Linted tests.
* (d3-force) [Chore]: Added tslint.json to disable "unified-signatures" rule
* (d3-force) [Chore]: Completed linting.
* (d3-selection) [Chore]: Added tslint.json to disable "unified-signatures" rule
* (d3-selection) [Fix]: Changed `CustomEventParameters` and `NamespaceLocalObject` and `NamespaceMap` to be interfaces as opposed to types.
* (d3-selection) [Chore]: Completed linting of defintion and tests,
* (d3-selection-multi) [Chore]: Added tslint.json to disable "unified-signatures" rule
* (d3-selection-multi) [Chore]: Completed linting of definition and tests. Used `// tslint:disable-next-line:interface-over-type-literal` for type alias ValueMap. Using type is better here for IDE hints, as the hint replaces alias with its content. This saves separate "peeking" as would be the case for interface. Also, there is no need to extend the type. For the entire test file `// tslint:disable:object-literal-shorthand` was applied, as the object literals actually need to use functions and not arrow function "short hand" ("this" context will be bound rather than lexically scoped)
* (d3-selection-multi) [Chore]: Minor JSDoc comment additions for completeness.
* (d3-transition) [Chore]: Added tslint.json to disable "unified-signatures" rule
* (d3-transition) [Chore]: Minor JSDoc comment additions for completeness.
* (d3-transition) [Chore]: Completed linting.
* (d3-zoom) [Chore]: Added tslint.json to disable "unified-signatures" rule
* (d3-zoom) [Chore]: Completed linting.
* strictNullChecks
* (d3-selection) [Fix]: Re-inserted `| null` into return type of `node()`. Fixed all tests, for mock-purposes using `!` post-fix where necessary. Note, this includes using post-fix on document.querySelector(...) which now also includes possible `null` return type.
* (d3-transition) [Fix]: Re-inserted `| null` into return type of `node()`. Fixed all tests, for mock-purposes using `!` post-fix where necessary. Note, this includes using post-fix on document.querySelector(...) which now also includes possible `null` return type.
* (d3-force) [Fix]: Moved return type of `force('forcename')` getter to include `| undefined` unconditionally. This is a change from allowing the casting using the generic to exclude `undefined`. This change was made for consistency with the treatment of e.g. `node()` (see above)
* (d3-drag) [Chore]: Adjust test to mock-assert non-null using `!` when using `node()`
* d3-zoom fix test
* (d3-zoom) [Chore] Needed to assert non-null node() return-type for testing purposes only.
* Update header comments to new convention
* Removed "v" from version header.
