dock: don't try to detect undocking, that doesn't work

Unplugging the dock while running seems harmful currently. Just use a
special command for that before undocking. On the other hand, docking
should just work.
compton: don't use glx backend

It doesn't work well with newer Intel drivers.
terminal: darker background
terminal: don't keep "Terminal" in the title
terminal: switch to evilvte

With a custom compilation. It supports more stuff than xfce4-terminal,
notably italics. There are still a lot to do to have something as nice
as rxvt... Should be compiled with GTK3, otherwise, it will have the
same problems than xfce4-terminal.
compton: don't use DRM for vsync, ugly