[Bf-committers] development of conditional pass-thru node for compositor

[pete larabell]

not quite sure where this will end up, but it's working in it's
current form, thought i'd share a quick render

http://www.pasteall.org/pic/11269

basic idea is:

if(op1.pixel **TEST_HERE** op2.pixel){
    out.pixel = pass_if_true.pixel;    //the 3rd input
}else{
    out.pixel = pass_if_false.pixel;   // the 4th input
}

obviously that's pseudo-code. :)

current tests available are ==, !=, >, <, >=, <=

plan to allow full RGBA sockets for at least the bottom 2 inputs and
output socket.

Cheers!