(feat) pimped the mail part viewers

UI/WebServerResources/js/Mailer/Message.service.js

@@ -177,6 +177,7 @@
     var _this = this,
         parts = [],
         _visit = function(part) {
+          part.msgclass = 'msg-attachment-other';
           if (part.type == 'UIxMailPartAlternativeViewer') {
             _visit(_.find(part.content, function(alternatePart) {
               return part.preferredPart == alternatePart.contentType;
@@ -231,6 +232,9 @@
                 });
               }
 
+              if (part.type == 'UIxMailPartImageViewer')
+                part.msgclass = 'msg-attachment-image';
+
               // Trusted content that can be compiled (Angularly-speaking)
               part.compile = true;
               parts.push(part);