file cleanup on server
add missing icon in painting mode + remove a painting  notification after closing the painting mode
Cahed time on webserver for proxy debugging
Correct various errors in the discussion object
Match the size of the usercolor icon with the other ones
Solve the problem with undefined user color
Prepare for painting object reintegration
- Implemented "virtual" cx and cy attribute which refer to an objects center
- added active and illustrating states
- added structures function (stucturing objects specify which objects they are structuring)
- fixed structuring logic