Imported firmware from Project Bike Lights

These are firmware source code files imported verbatim from
the Project Bike Lights, as of commit
c30006aaf666f7cff3a6ab949c613c2f8cc6163b:

http://www.fi.muni.cz/~kas/git/?p=bike-lights.git;a=tree;f=firmware;hb=c30006aaf666f7cff3a6ab949c613c2f8cc6163b

These will not run directly on Tinyboard - I just want to have
documented all the changes I plan to make against these source code
files (and possibly to merge some future patches into both projects).