Created a base package for plugin collection.
Moved resource files to own folder.
Moved utility classes to own subpackage.
Renamed facetree plugin to unfold_plugin.
renamed flatten_mesh to unfold_command.
Moved patch analyzer classes to own submodule.
Moved classes for automatic mesh unfolding to own submodule.
Moved patch creation classes to own submodule.
Moved facetree tool selection classes to own submodule.