[Cin] Today's GIT checkin includes 2 new features + miscellaneous

[Andrea paz]

> Andrea: did you try F_maskfun and get that working?

Unfortunately, I don't understand how F_maskfun works. At the
beginning, with the default parameters, the upper track with maskfun
is completely transparent. Acting on the various parameters, some
colors are solarized according to two thresholds (high and low), then
you decide how much to do the color change with the other parameters.
But I get bad results, unpredictable and that I do not understand.
Does anyone want to test this plugin?