Modified Mousetrap definition to allow Mousetrap to be loaded as an

external module.

- tests are also updated to test loading as an external module
- mousetrap exports itself as an AMD module when an AMD define function is
  present

mousetrap/mousetrap-tests.ts

@@ -41,3 +41,11 @@ Mousetrap.trigger('esc');
 Mousetrap.trigger('esc', 'keyup');
 
 Mousetrap.reset();
+
+// Test that Mousetrap can be loaded as an external module.
+// Assume that if the externally-loaded module can be assigned to a variable with the type of global Mousetrap,
+// then everything is working correctly.
+
+import importedMousetrap = require('mousetrap');
+var mousetrapModuleReference: typeof Mousetrap = importedMousetrap;
+

mousetrap/mousetrap.d.ts

@@ -19,3 +19,7 @@ interface MousetrapStatic {
 }
 
 declare var Mousetrap: MousetrapStatic;
+
+declare module "mousetrap" {
+    export = Mousetrap;
+}