Cleanup $q module

[thebigredgeek]

While working on a quick fix for the $q module, I noticed that it is quite dirty. Promise methods are repeated 2 or three times. I'd like to take a crack at cleaning it up. Can I submit a PR?

[petebacondarwin]

$q is a dangerous beast. If you feel you could refactor it to improve it without breaking it or making it slower then please do have a go. I can't guarantee that it will get into the next release because at the moment we are frantic trying to tie up any regressions before releasing 1.2.

[thebigredgeek]

Cool. I'll give it a go. I don't want to refactor the logic, just DRY it up by referencing the same areas. I'll go ahead and fix #4165 before doing that

[thebigredgeek]

Also, I would like to add $q.resolve as the inverse of $q.reject. Thoughts?

[petebacondarwin]

See this comment from @IgorMinar : #3044 (comment)

[btford]

We have the promise spec as part of our tests now, so go for it. Just make sure your changes pass the tests.

[Narretz]

Closing this as a dupe of #5223