set /mnt perms correctly (#1648) to master

The fix here is to have a script that will run on machine startup to force /mnt to 1777 permissions.  The commit log shows me first trying an upstart script, which worked sometimes, but not consistently.  I can't figure out how upstart orders scripts, nor can I figure out how to make this go late in the bringup process, so I switched to a normal "init.d" style script, linked off of runlevel 2.

While I was in here I installed [mosh](http://mosh.mit.edu/) to better support lossy links and fixed the term color problem that we've had for a long time (#1961).

Assigning to @jrbl but if you want to pick up @jbau that'd be fine too.