Improved checkstlye xml

Added check for tab characters, removed final parameter warning
Changed Checkstyle again

Less final parameters, more whitespaces
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'origin/master'
Implemented GraphEventInterface
Started work on InternalMouseAdapter
Added panning (still buggy around the borders though)
Changed GraphManipulationInterface to use java.awt.Color for colors
set various small settings of mxGraphComponent on creation
fixed several checkstyle warnings