Implemented color groups

 - groups of similar items should be put inside an element with class "lcars-group-N", with N from 1 to 50
 - child items (the first 50 only) will be assigned a random color, all children in a group will receive the same hue, but unique saturation and luminance

Renamed lcars-generate to lcars-loop
 - Modified the old standalone generate method to pull out a more generic .loop method
 - implemented a .loop2 method with 2 nested loops

Signed-off-by: Martin Evans <martindevans@gmail.com>