new Lua script: palette extender

[GoogleCodeExporter]

http://pastebin.com/ZRbSYzqd

i'm struggling for a better name for this - what it does is to choose and take 
the first indexed colours, and randomize a mixture of them in the next ones

Original issue reported on code.google.com by nitrofur...@gmail.com on 11 Mar 2015 at 11:44