When restarting i3 check for connected second monitor: scale it and
restart polybar if there is one.
Put polybar tray on the main monitor.
Do not kill polybar and relaunch it when restarting i3, but restart it
using ipc (much faster).
Switch from gnome-terminal to st (see fork on github).
Open new terminal by default in the same working-dir as current window.
Modify scratchpad-terminal to work with every terminal.
