Fix navigation bug

The href="#" was troubling the view that the history appeared just for
a few milliseconds... the button with given onclick event does work now.

src/style.css

@@ -425,4 +425,9 @@ select {
 .tag-history-element .container div.value,
 .tag-history-element .parent div.value {
   font-size: 12px;
+}
+
+tag-history-button button {
+  background: none;
+  border: none;
 }

src/tags/app.tag

@@ -68,6 +68,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
     });
     route('/taghistory/image/*/tag/*', function(image, tag) {
       route.routeName = 'taghistory';
+      console.log("Route Taghistory");
 
       registryUI.taghistory.image = image;
       registryUI.taghistory.tag = tag;

src/tags/tag-history-button.tag

@@ -15,9 +15,9 @@ You should have received a copy of the GNU Affero General Public License
 along with this program. If not, see <http://www.gnu.org/licenses/>.
 -->
 <tag-history-button>
-  <a href="#" title="This will show the history of given tag"
+  <button title="This will show the history of given tag"
      onclick="registryUI.taghistory.go('{ opts.image.name }', '{ opts.image.tag }');">
     <i class="material-icons">history</i>
-  </a>
+  </button>
 
 </tag-history-button>