Major changes

- Extended description of c4dtools.utils.vmin(), ~.vmax(), ~.vbbmid().
- Added c4dtools.utils.current_state_to_object() and ~.clsname().
- Added docstrings for c4dtools.utils.Watch class.
- Changed docstrings of c4dtools.utils.FileChangedChecker class.
- Added c4dtools.utils.Filename class.
Added Library implementation

Libraries can now be used to communicate between plugins.
Added bounding-box helper class
no changes

dunno why github app wants to commit that file..