Updated breaking methodology

-Broken parts now in a dictionary for easier updating
-BrokenParts can now be updated
-BrokenPart: ID and partname now internal
-BreakablePart no longer relies on the child class to define
BreakRandom() (Though that's still not implemented)
-Broken parts get registered now
-GUI update: Changed access method to Backend.BrokenParts (In keeping
with List<> --> Dictionary<,> change)