Implement an interactive mode

[0xricksanchez]

I think it would be quite nice to have some kind of interactive shell mode

$ ./start_kgdb -i
$LIKE-DBG> kill  # To kill the current instance but keep the interactive mode intact
$LIKE-DBG> rerun # Rerun the same environment as the one that just ran before killing it
$LIKE-DBG> (un)pack # Syntax to be specified to (un)pack cpio archive
$LIKE-DBG> ctf kernel image  # To run a CTF instance
$LIKE-DBG> set mycfg.ini # To set mycfg.ini as the user.ini for all future runs
$LIKE-DBG> open exploit.c  # Should probably spawn a new tmux tab with the exploit opened in vim..
$LIKE-DBG> exit  # Exit interactive mode

The above syntax is just an example.
The shown commands are just examples as well.