- fix copyright stuff in various files:
   - remove e-mail addresses that don't exist anymore, but of course keep
     the names
   - change license from GPL to LGPL in dvb_i2c.h (Convergence code)
   - change license from GPL to LGPL in dvb_ringbuffer.h (ack by original
     author Oliver Endriss)
   - add LGPL license to dvb_functions