Charging curves from files

[Guy]

On my linux gear, charging a curve from a file for the tonal module opens directly the ‘~/.config/ART/profiles’ directory. It’s not the case for the contrast local and the haze removal modules, then we have to fill the whole path to open the right directory. The problem occurs each time we open ART, not after we have filled the path in the same session.

[agriggio]

better default location for loading curves in dehaze and local contrast

Fixes #69

→ <<cset 80c03e8f4905>>