Fixed ROI color issue, MembraneGui 3
Hooked up Find QD button
For some reason, having a trasparent layer doesn't work with two figures. Also, cleaned up boundary detection.

Instead of merging cells, I now use a for loop to plot the different
cells.
Fixed some issues with membrane patching, also made a method to find edges so it is easier to remove or add membranes. Adding works in GUI. Also, distance calculations work now.