Tighter ssh/byobu support for remote split screen

Now split screen is officially supported by Guake, and with session backup, this makes guake quite ideal for every day work (to my very biased opinion). However, on tab connected to remote systems (ex: ssh), this makes less pleasant to work (at least not the same level of pleasantness). Maybe we can find some idea:
- automatically ssh on tab restaure: ok but we need to keep track the previous working dir on the remote system
- tighter integration with byobu: on local, split screen shortcut works with the split screen feature of guake, if byobu is launched on the terminal (local or remote), a special byobu-compatible mode is triggered so that the shortcut stay the same, but byobu is used. This allow to restore the tab next time we ssh to the remote system