disconnect added

as there where still problems with the timer, disconnecting the signals
works fine.
Random starting player fixed, wasn't working right.
Added dialogbox to game finished, to have players get a look on the
field.
moved connects + fixed gamecrash on draw
smaller code
highlighting
ups
Merge pull request #37 from wladi-do/master

highlighting fix
Merge pull request #34 from smikosch/master

player 1 can be ai + fixes
Fix setting player color in pvp mode

kudos to @smikosch for finding the issue
Fix #38
introduce an approx. 2cm safety margin
sleep for 10ms in ARToolkit-less ARToolkitWidget::timerEvent
Program relied on pointer-type-keys in a QMap to be in insertion order when queried through QMap::keys()