RFC: rename brightness/contrast filter

[Cyrille Berger]

Hi,

I think we have a serious problem about it, maybe because they were "twisted" 
by their previous use of photoshop/paintshop/the gimp/whatever, but most 
people think that the brightness/contrast filter is the one which ask an 
integer adjustment of the contrast and the brightness.

In reallity the problem is reversed, I have answer on irc or by mail, 
countless of people looking for the curve adjustement in krita (I don't 
imagine the number of people who think that krita can't do it). We need to 
fix that problem.

I think we need to rename this filter.

Here is a few proposition:
- brightness / contrast curves
- brightness adjustement curves
- constrast adjustement curves
- lightness (adjustement) curves

-- 
--- Cyrille Berger ---