Remove binding between RoomListForm and RoomForm and reformat code.

This commit allows user to do a series of operations(via press and hold)
on a room without entering the room in RoomForm.
Fixes #14.

qml/form/RoomForm.qml

@@ -10,7 +10,7 @@ import "qrc:/js/md.js" as Markdown
 
 Item {
     id: item
-    property var currentRoom
+    property var currentRoom: null
 
     Pane {
         anchors.fill: parent