docs(guides/providers): fix typo

Closes #5465
chore(triaging.md): update triaging guidelines

I removed the complexity metric as suggested by this blog post on triaging:
http://www.lostgarden.com/2008/05/improving-bug-triage-with-user-pain.html
(see The temptation to assign ‘cost’)

Big thanks to @ashleygwilliams and @davidjnelson for their help and feedback!
docs(core): update fromJson return values

Dates are not returned, so remove Date from list of return values.

Closes #3070
feat($animate): animate dirty, pristine, valid, invalid for form/fields

Add css animations when form or field status change to/from dirty,
pristine, valid or invalid. This works like animation system present
with ngClass, ngShow, etc.

Closes #5378
fix($animate): delegate down to addClass/removeClass if setClass is not found

Closes #6463
docs(ngAnimate): add missing 'super' to addClass
docs(tutorial/step-05): fix path for 'phones.json'

Closes #5460