fix($animate): insert elements at the start of the parent container instead of at the end

With 1.2.x, `$animate.enter` and `$animate.move` both insert the element at the end of the provided
parent container element when only the `parent` element is provided. If an `after` element is provided
then they will place the inserted element after that one. This works fine, but there is no way to
place an item at the top of the provided parent container using these two APIs.

With this change, if the `after` argument is not specified for either `$animate.enter` or `$animate.move`,
the new child element will be inserted into the first position of the parent container element.

Closes #4934
Closes #6275

BREAKING CHANGE: $animate will no longer default the after parameter to the last element of the parent
container. Instead, when after is not specified, the new element will be inserted as the first child of
the parent container.

To update existing code, change all instances of `$animate.enter()` or `$animate.move()` from:

`$animate.enter(element, parent);`

to:

`$animate.enter(element, parent, angular.element(parent[0].lastChild));`
chore(CHANGELOG.md): add changelog for 1.2.16 and 1.3.0-beta.5
chore(CHANGELOG.md): add missing changes to 1.2.16 release
chore(CHANGELOG.md): add missing 1.2.15 changelog
docs(tutorial): fix linked files to bower_components folder

Closes #6960
docs(guide/scope): small fixes
docs(tutorial): synch step 0 with angular-seed
docs(tutorial): clean up and elaborate introduction
chore(docs/app/tutorials): improve helper directives
docs(tutorial): synchronize with angular-phonecat changes
docs(tutorial/step-8): module must be loaded in test

Closes #6930
feat(ngModelOptions): custom triggers and debounce of ngModel updates

By default, any change to an input will trigger an immediate model update,
form validation and run a $digest. This is not always desirable, especially
when you have a large number of bindings to update.

This PR implements a new directive `ngModelOptions`, which allow you to
override this default behavior in several ways. It is implemented as an
attribute, to which you pass an Angular expression, which evaluates to an
**options** object.

All inputs, using ngModel, will search for this directive in their ancestors
and use it if found.  This makes it easy to provide options for a whole
form or even the whole page, as well as specifying exceptions for
individual inputs.

* You can specify what events trigger an update to the model by providing
  an `updateOn` property on the **options** object. This property takes a
  string containing a space separated list of events.

  For example, `ng-model-options="{ updateOn: 'blur' }"` will update the
  model only after the input loses focus.

  There is a special pseudo-event, called "default", which maps to the
  default event used by the input box normally. This is useful if you
  want to keep the default behavior and just add new events.

* You can specify a debounce delay, how long to wait after the last triggering
  event before updating the model, by providing a `debounce` property on
  the **options** object.

  This property can be a simple number, the
  debounce delay for all events. For example,
  `ng-model-options="{ debounce: 500 }" will ensure the model is updated
  only when there has been a period 500ms since the last triggering event.

  The property can also be an object, where the keys map to events and
  the values are a corresponding debounce delay for that event.
  This can be useful to force immediate updates on some specific
  circumstances (like blur events). For example,
  `ng-model-options="{ updateOn: 'default blur', debounce: { default: 500, blur: 0} }"`

This commit also brings to an end one of the longest running Pull Requests
in the history of AngularJS (#2129)!  A testament to the patience of @lrlopez.

Closes #1285, #2129, #6945
fix($animate): ensure class-based animations always perform a domOperation if skipped

Closes #6957
docs(guide/tutorial): make added assertion one which will actually work.

Update the by.binding usage to make the test case work.

Closes #6987
docs(tutorial): change regexp so that assertion works

Need to remove this single space for the regex to work here.

Apparently `getText()` is trimming the text content or something, because there is no good reason
why that space should not be there.

Closes #6985
fix($compile): fix regression which affected old jQuery releases

ddb8081 and 4ea57e7 removed the calls which trimmed leading and trailing whitespace from templates
in the HTML compiler. This broke old versions of jQuery (such as 1.9.1), which do not trim
whitespace in their constructors. Naturally, this would not appear in the jQuery tests, as we are
testing against a version which does trim whitespace in the constructor.

This fix re-adds calls to `trim()` when compiling templates in $compile, in order to avoid breaking
old versions of jQuery.
docs(tutorial): fix links to bower in Step 11

Minor change: add missing bower reference link.

Closes #7005
docs(CONTRIBUTING.md): typo fix

"submitting and issue" should be "submitting an issue"

Closes #7002
docs(guide/directive): grammatical fixup

The 'to' in 'end-to-end' is directional, not numeric

Closes #6895
docs(tutorial): added a link to Wiki page on DI in Step 7

This article is fantastic and really helped on understanding how DI works on Angular. It may be
useful to other beginners -- because, at first glance, this topic (DI on Angular) ended a little bit
hazy for me.

Closes #7010