Improve liblights and adapt to module changes.

Enable support for more patterns:
- support different pattern speeds and brightness levels.
- support some special patterns (try setting "custom" speed)
- support for different brightness levels for each of the 6 leds
  by mapping each of the 6 color hex-digits to one led in the order
  menu, home, back, search, blueleft, blueright.
  The color 0x770007 for example will illuminate menu+home with
  medium white and back+search (i.e. blueright) with medium blue.

This change depends on the new kernel led module (bd2802) as it uses
the new sysfs interface provided by it.

Change-Id: I49cb69d1fe6ef274bd2ed58e1a703e4a7463ce57