docs(minerr/unpr): note that ctrls cant depend on other ctrls
docs(guide/forms): improve example

When explaining ng-model-options, there's no print of `user.data` to show
the difference between the default behaviour and updateOn: 'blur'
fix(compile): sanitize srcset attribute

Applies similar sanitization as is applie to img[src] to img[srcset],
while adapting to the different semantics and syntax of srcset.
perf(ngForm,ngModel): move initial addClass to the compile phase

Closes #8268
fix(ngView): use animation promises ensure that only one leave animation occurs at a time

the tracking depended on a local flag variable, which was susceptible to corruption due to
race conditions.

using promises ensures that the previousLeaveAnimation is nulled out only if it hasn't been
canceled yet.

Closes #9355
Closes #7606
Closes #9374
fix(input): correctly handle invalid model values for `input[date/time/…]`

Similar to `input[number]` Angular will throw if the model value
for a `input[date]` is not a `Date` object.
For `Invalid Date`s (dates whose `getTime()` is `NaN`) `input[date]`
will render an empty string.

Closes #8949
Closes #9375