Added Line class, changed draw window
Added buttons to select the desired action
adjusted the distance between the node and the line, created new interface to insert UBeams
Add the feature to split edges and the interface to create Ubeam
Added Straight line interface
Added force interface
Separeted classes in packages, add number of nodes on UBend interface
Fixed bug on edge length, alterated method of try and done buttons
Minor changes on restrains handling
merging