fixed issue #31
solution: iterated through nodelist and took the first found "optical"
collision, calculated a compensation vector, so the node will jump to
the correct side of the colliding node AFTER releasing the mouse.
sadly recursive procedure does not work here. so if after a resolved
collision, the new position collides with another node, nothing happens.
Merge branch 'master' of https://github.com/eugenkiss/genericproject.git