docs(CHANGELOG): fix code snippets

A few snippets were not wrapped in code blocks.

Closes #2245
docs(typeahead): use array.map to shorten async example
feat(modal): support alternative controllerAs syntax

Fixes #2242
fix(modal): allow in-lined controller-as controllers
docs(README): fix code samples formatting
feat(modal): allow templateUrl to be a function

Fixes #2296
test(modal): Remove `ddescribe` in the $modal tests

The `ddescribe` is only executing the $modal tests. Removing it will allow
all other unit tests to run.

Fixes #2311.
chore(Gruntfile): add `grunt-ddescribe-iit` task to CI checks

This should prevent `ddescribe` and `iit` blocks in tests from being checked into the tree, as they
were in #2311.
fix(datepicker): correct `datepicker-mode` binding for popup

Fixes #2180
Closes #2184
fix(modal): respect autofocus on child elements

Auto-focusing of a freshly-opened modal element causes any child
elements with the autofocus attribute to loose focus. This is an issue
on touch based devices which will show and then hide the onscreen
keyboard. Attempts to refocus the autofocus element via JavaScript will
not reopen the onscreen keyboard. Fixed by updated the focusing logic to
only autofocus the modal element if the modal does not contain an
autofocus element.

Fixes #1696
Closes #1892
Closes #2273
fix(dropdown): remove `C` restrictions to avoid conflicts

Fixes #2156

BREAKING CHANGES: Both `dropdown` and `dropdown-toggle` are only attribute directives

Before:
  ```html
  <btutton class="dropdown-toggle" ...>
  ```
  After:
  ```html
  <btutton class="dropdown-toggle" dropdown-toggle ...>
  ```

Closes #2170
docs(CONTRIBUTING.md): clarify GitHub issues handling policy
feat(accordion): Toggle on header click
fix(tooltip): when hiding tooltip, ensure digst is not inprogress ...

... when calling $apply()
fix(tooltip): use $digset instead of $apply when hiding tooltip ...

... applying a scope will cause the whole app to $digest