Improve JavaScript of Mail module

- activated file uploader of mail editor
- renamed method $update to $reload
- automatically mark messages as read
- use ui-sref-active from ui-router instead of ng-class

UI/WebServerResources/js/mobile/MailerUI.js

@@ -96,7 +96,7 @@
               return _find(stateAccount.$mailboxes);
             }],
             stateMessages: ['stateMailbox', function(stateMailbox) {
-              return stateMailbox.$update();
+              return stateMailbox.$reload();
             }]
           }
         })