[Core/Promises] Added the base Promise types: Fulfilled and Rejected.
[Core/Promises] Added the Deferred promise type.
[Core/Promises] Added a Promise Resolver interface.
[Core/Promises] Added a placeholder README for the subcomponent.
[Core/Promises] Added a Deferred Resolver.
[Core/Promises] Updated the Resolver interface docs to expect a return value (the current instance of the Resolver).
[Core/Promises] Unnecessary imports.
[Core/Promises] Added a Deferred class which combines the Promise/Resolver API.
[Utils/When] Docblocks and CS.