templatematch: Match rectangle grows redder with increased match certainty
templatematch: Match rectangle grows redder with increased match certainty

This only works with match methods 1, 3 & 5 (where the match certainty
is normalised to 1.0).

LewisHaley/stb-tester,LewisHaley/stb-tester,wmanley/stb-tester,wmanley/stb-tester,wmanley/stb-tester,LewisHaley/stb-tester,martynjarvis/stb-tester,martynjarvis/stb-tester,wmanley/stb-tester,martynjarvis/stb-tester,martynjarvis/stb-tester,stb-tester/stb-tester,LewisHaley/stb-tester,wmanley/stb-tester,martynjarvis/stb-tester,LewisHaley/stb-tester,stb-tester/stb-tester,stb-tester/stb-tester,martynjarvis/stb-tester,martynjarvis/stb-tester,LewisHaley/stb-tester,LewisHaley/stb-tester,stb-tester/stb-tester