Add hover helper text to refresh and clear buttons

ckanext/harvest/templates_new/source/admin_base.html

@@ -13,15 +13,17 @@
   {% else %}
     {% set locale = h.dump_json({'content': _('This will re-run the harvesting for this source. Any updates at the source will overwrite the local datasets. Sources with a large number of datasets may take a significant amount of time to finish harvesting. Please confirm you would like us to start reharvesting.')}) %}
     <li>
-      <a href="{{ h.url_for('harvest_refresh', id=source.id) }}" class="btn" data-module="confirm-action" data-module-i18n="{{ locale }}">
+      <a href="{{ h.url_for('harvest_refresh', id=source.id) }}" class="btn" data-module="confirm-action" data-module-i18n="{{ locale }}"
+         title="{{ _('Start a new harvesting job for this harvest source now') }}">
         <i class="icon-refresh"></i>
         {{ _('Reharvest') }}
       </a>
     </li>
   {% endif %}
     {% set locale = h.dump_json({'content': _('Warning: This will remove all datasets for this source, as well as all previous job reports. Are you sure you want to continue?')}) %}
     <li>
-      <a href="{{ h.url_for('harvest_clear', id=source.id) }}" class="btn" data-module="confirm-action" data-module-i18n="{{ locale }}">
+      <a href="{{ h.url_for('harvest_clear', id=source.id) }}" class="btn" data-module="confirm-action" data-module-i18n="{{ locale }}"
+         title="{{ _('Delete all harvest jobs and existing datasets from this source') }}">
         {{ _('Clear') }}
       </a>
     </li>