color: move git-subrepo support into the subrepo module Now that all ui instance carry a '_colormode' attribute, we can access and comply to it directly in the subrepo code. The actual implementation could probably be a bit smarter, but we stick close to the current one for the sake of simplicity.

color: move 'modesetup' into the core module Yet another piece of code moving from the extensions to the module in core!

color: move 'terminfosetup' into the core module Another step closer to have all the logic living in core