* Added exports for functions format(name: string, fmt: string | Function): Function and compile(format: string): Function to morgan namespace. These fnctions are exported in the morgan js module and can be used in conjunction with the token function to create named custom formats. Inncluded tests.
* Added interface definitions to clarify the signatures of callback function used in defining custom tokens (TokenCallbackFn) with morgan.token(...). Added interface definitions to clarify signatures of custom format functions returned by morgan.compile(...) and used as arguments to morgan.format(...) and morgan(...). Added interface Morgan to clarify return type of morgan.token(...), morgan.compile(...) and morgan.format(...). For a detailed discussion of the rationale of there changes see comments in pull request #9364. Updated tests.
Updated version reference to morgan 1.7.0.
