Update various template files to increase accessibility support.

Signed-off-by: Brandon Raitt <npm.pxoink@gmail.com>

templates/part.board.mainView.php

@@ -119,7 +119,7 @@
 							   required placeholder="<?php p($l->t('Enter a card title')); ?>"/>
 					</h4>
 				</form>
-				<div ng-if="!status.addCard[s.id]" ng-click="status.addCard[s.id]=true">
+				<div ng-if="!status.addCard[s.id]" ng-click="status.addCard[s.id]=true" title="<?php p($l->t('Add card')); ?>">
 					<i class="icon icon-add{{ boardservice.getCurrent().color | iconWhiteFilter }}"></i>
 				</div>
 			</div>