docs(errors/infdig): add a common example

Mention common cause of error is binding to a new array on every $digest loop.

Closes #6465
docs(guide): add a new django tutorial

 - add a link to a tutorial on intergrating angular and django
docs(guide/resource): add links to ngResource and $resource
docs($injector): fix typo

Duplicate 'that' words present in the document, just remove one of them.

Closes #6469
docs(changelog): fix typos
chore(scripts): fix typos in scripts/utils.inc
docs($compile): fix typo
docs($sce): fix typo
chore(animate): fix typo in a comment
chore(AngularSpec): fix typo
chore(ngRepeatSpec): fix typo
chore(filtersSpec): fix typo
chore(httpSpec): fix typo
chore(parseSpec): fix typo
chore(qSpec): fix typos
fix(jqLite): properly toggle multiple classes

Fixes #4467
Closes #6448
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