feat(pagination): add classes to assist with styling

- Add classes to allow the user to target the styles of component with more specificity

Closes angular-ui#4130

Author: wesleycho

Diff for: template/pagination/pagination.html

@@ -1,7 +1,7 @@
 <ul class="pagination">
-  <li ng-if="::boundaryLinks" ng-class="{disabled: noPrevious()||ngDisabled}"><a href ng-click="selectPage(1, $event)">{{::getText('first')}}</a></li>
-  <li ng-if="::directionLinks" ng-class="{disabled: noPrevious()||ngDisabled}"><a href ng-click="selectPage(page - 1, $event)">{{::getText('previous')}}</a></li>
-  <li ng-repeat="page in pages track by $index" ng-class="{active: page.active,disabled: ngDisabled&&!page.active}"><a href ng-click="selectPage(page.number, $event)">{{page.text}}</a></li>
-  <li ng-if="::directionLinks" ng-class="{disabled: noNext()||ngDisabled}"><a href ng-click="selectPage(page + 1, $event)">{{::getText('next')}}</a></li>
-  <li ng-if="::boundaryLinks" ng-class="{disabled: noNext()||ngDisabled}"><a href ng-click="selectPage(totalPages, $event)">{{::getText('last')}}</a></li>
+  <li ng-if="::boundaryLinks" ng-class="{disabled: noPrevious()||ngDisabled}" class="pagination-first"><a href ng-click="selectPage(1, $event)">{{::getText('first')}}</a></li>
+  <li ng-if="::directionLinks" ng-class="{disabled: noPrevious()||ngDisabled}"><a href ng-click="selectPage(page - 1, $event)" class="pagination-prev">{{::getText('previous')}}</a></li>
+  <li ng-repeat="page in pages track by $index" ng-class="{active: page.active,disabled: ngDisabled&&!page.active}" class="pagination-page"><a href ng-click="selectPage(page.number, $event)">{{page.text}}</a></li>
+  <li ng-if="::directionLinks" ng-class="{disabled: noNext()||ngDisabled}"><a href ng-click="selectPage(page + 1, $event)" class="pagination-next">{{::getText('next')}}</a></li>
+  <li ng-if="::boundaryLinks" ng-class="{disabled: noNext()||ngDisabled}" class="pagination-last"><a href ng-click="selectPage(totalPages, $event)">{{::getText('last')}}</a></li>
 </ul>