fix(minErr): stringify non-JSON compatible objects in error messages

Fix the JSON stringification to output a more meaningful string when an
object cannot be normally converted to a JSON string, such as when the
object contains cyclic references that would cause `JSON.stringify()`
to throw an error.

Closes #10085
fix(ngRepeat): support cyclic object references in error messages

Now that `minErr` can cope with objects that cannot be normally stringified
to JSON, just pass the error arguments straight through without trying to
stringify them first.

Closes #9838
Closes #10065
Closes #10085
fix($rootScope): handle cyclic references in scopes when creating error messages

Use the new private function `stringify` to convert scope values to strings,
since this can cope with cyclic references and other oddities.

Closes #10085
docs(tutorial/step-4): "unknown" option is actually blank

The name 'unknown' doesn't appear as a choice, the new choice is just blank.
Side note: once I choose one of the non-blank options, I no longer see the blank option.

Closes #10079
docs(tutorial/step-5): include sort and filter in json view experiment

Closes #10082
docs($anchorScrollProvider): remove repeated word

Closes #10093
chore(docs): add favicon to docs app
test(ngModel): group validation tests
fix(ngModel): don't run parsers when executing $validate

Previously, $validate would execute the parsers to obtain a
modelValue for validation. This was necessary, because a validator
that is called outside of model / view update (e.g. from an observer)
otherwise might only an undefined modelValue, because a previous
view update has found a validation $error and set the model
to undefined (as is tradition in angular)

This is problematic as validators that are run immediately after
the ngModelController initializes would parse the modelValue
and replace the model, even though there had been no user input.

The solution is to go back to an older design: the ngModelController
will now internally record the $$rawModelValue. This means a model
or view update will store the set / parsed modelValue regardless
of validity, that is, it will never set it to undefined because of
validation errors.

When $validate is called, the $$rawModelValue will passed to the
validators. If the validity has changed, the usual behavior is kept:
if it became invalid, set the model to undefined, if valid,
restore the last available modelValue - the $$rawModelValue.

Additionally, $validate will only update the model when the validity
changed. This is to prevent setting initially invalid models other
than undefined to undefined (see #9063)

Fixes: #9063
Fixes: #9959
Fixes: #9996
Fixes: #10025

Closes: #9890
Closes: #9913
Closes: #9997
Closes: #10048
fix(NgModelController): typo $rawModelValue -> $$rawModelValue
docs(CHANGELOG): add 1.3.3 changes
chore(docs): update to dgeni-packages 0.10.7

This update to dgeni-packages fixes some trimIndentation issues

Closes #10101
docs($location): fix method-name and typos in `ihshprfx` error

Closes #10106
fix($http): return empty headers, ignore properties in Object prototype

Fix response headers with an empty value Empty response header values are legal
(http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html).

The headers getter fn will now only return null if the header property is not an own property.

Closes #7779
Closes #10113
Closes #10091
feat(ngPluralize): add support for `count` to be a one-time expression

Closes #10004
docs(jqLite): clarify that Debug Data must be enabled for scope/isolateScope methods

Closes #9515
Closes #10123
feat(ngModelController): add $setDirty method

- extract existing functionality to public method: $setDirty
- add tests to corresponding changes
- refactor code to use extracted method

Closes #10038
Closes #10049
doc(ngModelController): move example below members
docs(CHANGELOG): update changelog with 1.2.27
docs(ngModelController): update wordings, add more general info

The wordings in setDirty etc. were specific to inputs, but ngModelCtrl
is agnostic to this and the preferred term is 'control'. I also
added some more info about this to the description, and linked to
the example that now lives at the bottom of the page.