- Improved @rules so that it now contains hash of hashes instead of hash of arrays.
- Improved Controller::apply_rule method, which now takes care of deleting shapes which completely overlap.
- Added Controller::remove_shape method which takes care of cleaning up all variables when shape needs to be deleted.
- Added basic UI to initialize ISG Controller and generate design.
- Improved Controller::apply_rule method so that it now returns false when new shapes only replace old ones...