fix(typeahead): plug in front of existing parsers

Closes #863
feat(modal): rewrite $dialog as $modal

BREAKING CHANGE:
* `$dialog` service was refactored into `$modal`
* `modal` directive was removed - use the `$modal` service instead

Check the documentation for the `$modal` service to migrate from `$dialog`
fix(tabs): evaluate `vertical` on parent scope

Closes #849.
feat(pagination): `total-items` & optional `items-per-page` API

Closes #820.

BREAKING CHANGE: API has undergone some changes in order to be easier to use.
 * `current-page` is replaced from `page`.
 * Number of pages is not defined by `num-pages`, but from `total-items` &
  `items-per-page` instead. If `items-per-page` is missing, default is 10.
 * `num-pages` still exists but is just readonly.

  Before:

  <pagination num-pages="10" ...></pagination>

  After:

  <pagination total-items="100" ...></pagination>
feat(rating): add support for custom icons per instance
docs(README): clarify IE8 support
fix(modal): insert backdrop before modal window
fix(modal): ie8 fix after $modal rewrite
refactor(rating): moving default class names back to template
fix(typeahead): highlight return match if no query

This makes the highlighter behave more consistently like other filters.

It also makes it more useful as an empty query doesn't result in an
empty result.
fix(typeahead): keep pop-up on clicking input

Also, keep reference to event listener to unbind when scope is
destroyed. (Memory leak)
fix(position): fallback for IE8's scrollTop/Left for offset
chore(build): update custom build to use $modal service

Closes #927
fix(typeahead): remove dependency on ng-bind-html-unsafe

Closes #813
fix(timepicker): add type attribute for meridian button
fix(datepicker): use $setViewValue for inner changes

Closes #855
fix(modal): opening a modal should not change default options

Closes #935
docs(README): clarify IE8 support

Closes #901
feat(modal): add support for custom window settings

Closes #892
fix(modal): backdrop should cover previously opened modals

Closes #922
Closes #931