drag simulation done
modelnode hovering
added copy/delete/paste selection methods
outcommented useless pressmouseevent
implemented drag modules into group
selected items now on the front, groundwork for realesemouseevent
implemented cut (STRG+X)
moving selection & group hovering implemented
sim::mousemoveevent improved code, fixed group over group bug
renamed hoveredNode -> hoveredGroupNode
paste modules into group done
fixed bug: group in group movement
fixed groupnode::isgroup and inner group movements