Fixed random flickering bug when received data via UART

  Previously the LEDs would flash everytime a new frame
   was received due to insufficient processing time being
   available.
  I have increased the time between switching between each
   LED colour (effectively doubled) from a on time of ~ 0.5ms
   to 1ms. This reduces the amount of time spent in interrupt
   routines, and also sending data to the TLC5940 driver ICs

  Additionally I have increased the number of comments in
   the code, and credited solderlab.de for the orignal version

  There is also a different gamma correction curve available
   for each colour should we find the time to calibrate it.