match refactor: Pass 4 channel template around instead of mask
match refactor: Pass 4 channel template around instead of mask

...and a 3 channel template.  This will be useful for whole screen
optimised matches.

stb-tester/stb-tester,stb-tester/stb-tester,stb-tester/stb-tester,stb-tester/stb-tester