Bugfixes (Huge), New Functions (Small)

>>> NEW FUNCTIONS <<<
- New Function: Windows (prefered information windows) will now always
appear in the middle of the screen rather than at the top left side
- Graphic: Slight graphical changes and grammar correction

>>> BUG FIXES <<<
- Fixed a bug where a panel was marked even if it was already in that
state (now only panels not assigned will be checked for marked status)
- Fixed a bug where a marked panel was instantly set as task state
"free" when admitted rather than as task state "assigned"
- Fixed a bug where marked panels had absolute priority rather than only
priority over not assigned panels, now you can correctly update other
panels even if another one is marked (assigned and other marked ones)