Tmux changes

 - make tmux behave like a proper editor
 - mouse mode is just much better. Especially since I've learnt you can
   copy in mouse mode by hitting y while text is selected before
   releasing the mouse
Make repo work with vagrant

This repo now adds a Vagrantfile that will use this repo to provision a
vagrant box using this repo. Meta.

Main things that needed to change were moving from using group_vars to
role_vars, which is a better fit for this sort of data anyhow.

Also needed to update some tasks to work correctly from within a vm -
stop using the data for home directory because ansible seems to do the
right thing with ~ anyhow.