X counts the middle button as 2 and right as 3, Qt as 4 and 2 resp. the flags
... we shall at least match our GUI ;-)
BUG: 314756
FIXED-IN: 4.10.1
REVIEW: 108883
happens when the polling misses the press when doing more
important things
also shortcut buttons == oldButtons
BUG: 314762
FIXED-IN: 4.10.1
REVIEW: 108883