revert back to github markdown style code examples, so they are compatible with ember's website.

Hopefully we can bring this back in the future.
Adds named function for promise callbacks

[Related PR](https://github.com/emberjs/ember.js/pull/3876).
remove fail, as catch is what the spec defines.

es3 users can use that `promise['catch']` syntax
Merge pull request #167 from twokul/relevant-stack-trace

Adds named function for promise callbacks
Merge github.com:tildeio/rsvp.js

Conflicts:
	lib/promise/promise.js
	lib/rsvp/defer.js
	lib/rsvp/events.js
	lib/rsvp/hash.js
	lib/rsvp/node.js
	lib/rsvp/rethrow.js
	test/tests/extension_test.js