Fixed segfault regression
* Segfault occurred when user would modify a barline array graph (for instance) and dragged the mouse outside its bounds and let go of the mouse button. This was because array issues glist_grab without e_grab being declared. * At the same time, array also relies on letting go of the grab once the mouse is let go, so we also need to do this in the mouseup function. Otherwise, one would be stuck dragging array even after letting go of the array.