Fix #62: teach getCFL() to parse the AV1 CfL design
Fix #62: teach getCFL() to parse the AV1 CfL design

Although they conceptually have 3 fractional bits of precision,
the AV1 spec v1.0.0 only refers to the integer representation.
Anyhow, "-3,1" is more compact than "-0.375,0.125" at least.
Display the pair over 2 lines on the UV mode overlay.

mbebenita/aomanalyzer,mbebenita/aomanalyzer,mbebenita/aomanalyzer