Commit Briefs
rework color management: introduce the trailing props
now, instead of prefix and line style, I'm adding the trailing style too. This changed the configuration syntax too.
work around some GCC warnings
clang doesn't emit any. To be honest, some of them are actually right (like the missing `void'), others are impossible but still it's not a bad idea to initialize some variable. Future me maybe will be thankful.
move all cmd_* functions in their own file
this detangles definitely the commands from the ui. Various variables and struct from ui.c needed to be exported, aside from that, no functional changes.