Step 6

- Added chat windows
- When user double click on a connected friend, it displays a chat
window for that friend that can be moved, reduced or closed.
- When user reduce window, messages history will be kept, otherwhile
when the user close the window, all messages will be erased.
- User can only send messages to his friend.
- Chat windows can be focused by clicking on it. Focus a window removes
the notifying state.
- When user receives a message and window isn't focused, window state is
switched to notifying (blink).
- If no window is opened while recieving the message, sender name will
glow in friend list.
- If friend list is closed, open/close button will glow.

This step also includes some bug fixes :
- Dragging out of drag bounds will now stop the dragging
- Dragging position is now properly centered to the dragged div
- Made the entire friend list unselectable due to anoying non-intended
selection
- Removed useless gologin and goregister