Bundle subdir themes

Purpose:
This subdir may optionally contain theme files which either replace part of the
theme or add files to the theme provided as default for APLAWS+ and this
way adopt the theme for site specific design. 

All files and subdirectories all copied asis to the applications ~/themes 
directory in its document (context) root.

It is the responsibility of developer / system integrator to ensure all files
are copied to the right location and the theme works with the modification. No
functionality or consistency check is performed!