Removed a bunch of old, dead code
Changed how modules are initialized; I'm not convinced this is the 'right' way to do it, but it's certainly better than the old way
Abstracted out the display_sessions code into the UiHandler module
The main command window now uses the same display code as the other windows. Sessions are displayed hierarchally now, which looks pretty sexy
Sessions no longer default to being called 'unnamed', they now default to something more obvious
Removed a bunch of callbacks that effectively do the same thing; replaced with a single callback for any kind of session error
The dnscat2 client now defaults to 'command' mode
Added a 'session' command to command-mode