Allow users to set custom promise permutations ahead of time
Change method name to thenApply to make it feel more promisey.

Also adds support for all of then. then(onFullfulled, onRejected, onProgress)
Reject the promise on errors
Fix up README
README clarification
Clarification for README endpoint.methods() method
Add links to Promises and Q docs in API Reference
More Q links
Explain thenApply use case.
Merge pull request #32 from kahnjw/allow_promise_permutation

Allow promise permutation