doc(angular.forEach): note difference from ES262's Array.prototype.forEach

Since Angular's forEach is not a strict polyfill, and takes different paths depending on the type
of collection it is dealing with, it does not throw a TypeError when converting the obj with
ToObject(), as this operation does not need to be performed.

This difference is documented nicely here.

Closes #9142
docs(input): `ngModel` uses priority 1
docs(guide/directive): fix typo
refactor($compile): simplify regular expressions

Closes #9637
refactor(jqLite): remove a duplicate DOMContentLoaded handler attachment
docs(jqLite): typo: `getComputedStyles()` -> `getComputedStyle()`