docs(migration): add a note about "private" properties being reverted

Closes #5086
docs(guide/compiler): add fourth step on appending the compiled template to the DOM

Closes #5087
docs(guide/providers): fix typo

Closes #5102
docs(guide/di): use square bracket notation for $inject annotation

Closes #5104
docs($injector): use square bracket notation for $inject annotation

Closes #5104
docs($window): move use of $window to controller

Move use of `$window` from template to controller, because accessing `$window`
in expressions is now disallowed and doesn't work.

Closes #5110
docs(guide/concepts): fix incorrect module name in example

Closes #5116
docs(form): provide a list of Angular's built-in validation tokens

As requested by a top-rated Disqus comment: http://docs.angularjs.org/api/ng.directive:form.FormController#comment-655325797

Closes #5121