More accessible pagination/navigation controls (#1609)

- Incorporates improvements from #1586 and #1587.
- Moves next/prev navigation to a shared template to reduce redundancy.

themes/bootstrap3/templates/search/pagination.phtml

 <?php if ($this->pageCount): ?>
-  <ul class="pagination">
+  <ul class="pagination" aria-label="<?=$this->transEsc('pagination_label')?>">
     <?php if (isset($this->previous)): ?>
       <?php if (!isset($this->options['disableFirst']) || !$this->options['disableFirst']): ?>
-        <li><a href="<?=$this->currentPath() . $this->results->getUrlQuery()->setPage(1)?>">[1]</a></li>
+        <li role="none">
+          <a href="<?=$this->currentPath() . $this->results->getUrlQuery()->setPage(1)?>" aria-label="<?=$this->transEsc('page_first')?>">[1]</a>
+        </li>
       <?php endif; ?>
-      <li><a class="page-prev" href="<?=$this->currentPath() . $this->results->getUrlQuery()->setPage($this->previous)?>"><span aria-hidden="true">&laquo;</span> <?=$this->transEsc('Prev')?></a></li>
+      <li role="none">
+        <a class="page-prev" href="<?=$this->currentPath() . $this->results->getUrlQuery()->setPage($this->previous)?>" aria-label="<?=$this->transEsc('page_prev')?>">
+          <i class="fa fa-angle-left" aria-hidden="true"></i>
+          <?=$this->transEsc('Prev')?>
+        </a>
+      </li>
     <?php endif; ?>
 
     <?php if (count($this->pagesInRange) > 1): ?>
       <?php foreach ($this->pagesInRange as $page): ?>
         <?php if ($page != $this->current): ?>
-          <li><a href="<?=$this->currentPath() . $this->results->getUrlQuery()->setPage($page)?>"><?=$page?></a></li>
+          <li role="none">
+            <a href="<?=$this->currentPath() . $this->results->getUrlQuery()->setPage($page)?>" aria-label="<?=$this->transEsc('page_no', ['%%page%%' => $page])?>"><?=$page?></a>
+          </li>
         <?php else: ?>
-          <li class="active" aria-current="page"><span><?=$page?></span></li>
+          <li role="none" class="active" aria-current="page"><span><?=$page?></span></li>
         <?php endif; ?>
       <?php endforeach; ?>
     <?php endif; ?>
 
     <?php if (isset($this->next)): ?>
-      <li><a class="page-next" href="<?=$this->currentPath() . $this->results->getUrlQuery()->setPage($this->next)?>"><?=$this->transEsc('Next');?> <span aria-hidden="true">&raquo;</span></a></li>
+      <li role="none">
+        <a class="page-next" href="<?=$this->currentPath() . $this->results->getUrlQuery()->setPage($this->next)?>" aria-label="<?=$this->transEsc('page_next')?>">
+          <?=$this->transEsc('Next');?>
+          <i class="fa fa-angle-right" aria-hidden="true"></i>
+        </a>
+      </li>
       <?php if (!isset($this->options['disableLast']) || !$this->options['disableLast']): ?>
-        <li><a href="<?=$this->currentPath() . $this->results->getUrlQuery()->setPage($this->pageCount)?>">[<?=$this->pageCount?>]</a></li>
+        <li role="none">
+          <a href="<?=$this->currentPath() . $this->results->getUrlQuery()->setPage($this->pageCount)?>" aria-label="<?=$this->transEsc('page_last')?>">[<?=$this->pageCount?>]</a>
+        </li>
       <?php endif; ?>
     <?php endif; ?>
   </ul>