perf($q): move Deferred and Promise methods to prototypes

Opening PR for tests and comparison with other solutions for `$q` perf.

NOTE: Deferred doesn't get all the advantages of moving methods to the prototype,
since the constructor binds instance methods to "this" to support unbounded execution.

NOTE: This change increases the gzipped version by 100 bytes.
these closures can mostly be moved out of `finally()` --- the implementation I wrote was able to reuse a lot more, and only wound up creating a single (iirc) callback per call