Experiment new ergonomics to interact with card details

The idea is that by displaying card details in a sidebar stuck on the
right of the screen, the mouse had to travel too much before
interacting with it. I also don’t want to use the Trello solution
(modal) on big screens, because I like the ability to interact with
the selected card and with the board at the same time (like in a
e-mail client).

The solution introduced in this commit consist of opening the card
detail in a column next to the minicard list.

This commit also fix right sidebar members and labels drag and drop.

client/lib/utils.js

@@ -18,18 +18,6 @@ Utils = {
     };
   },
 
-  Warning: {
-    get: function() {
-      return Session.get('warning');
-    },
-    open: function(desc) {
-      Session.set('warning', { desc: desc });
-    },
-    close: function() {
-      Session.set('warning', false);
-    }
-  },
-
   // XXX We should remove these two methods
   goBoardId: function(_id) {
     var board = Boards.findOne(_id);
@@ -49,12 +37,6 @@ Utils = {
     });
   },
 
-  liveEvent: function(events, callback) {
-    $(document).on(events, function() {
-      callback($(this));
-    });
-  },
-
   capitalize: function(string) {
     return string.charAt(0).toUpperCase() + string.slice(1);
   },