The basic idea is to replicate the same sort of functionality that this atom plugin (https://github.com/prrrnd/atom-git-projects) provides but for Sublime.
I really like Atom for its feature set but its just still too slow. This was one of the things that I missed when I went back to using Sublime.
I tried to get this working as a Python Plugin but I couldn't work out how to edit the session data once Sublime had started. Not to mention I have never coded a line of Python in my life and every line of code I had to google what to do.
TODO: Learn Python lol
Anyway this hacky PHP script combined with an inotify cron job does what I want. I now just have to clone a new project and start sublime and the project already exists.
NOTE: If Sublime is already running the session file wont get updated because when sublime closes it will overwrite it again.
http://www.cyberciti.biz/faq/linux-inotify-examples-to-replicate-directories/