emonPi custom bash prompt: RW indicator

Continuing the discussion from Increase emonSD pre-built SD card to 8GB min:

As suggested by @Andy_Taylor in the thread above we have implemented a custom bash prompt on the emonPi which alerts the user if the file-system is in read-only (ro) or read-write(rw) mode from the prompt e.g.

[email protected](ro):~$ 
[email protected](ro):~$ rpi-rw
Filesystem is unlocked - Write access
type ' rpi-ro ' to lock
[email protected](rw):~$ 

This updated prompt will be rolled out to all existing emonPis via emonPi update. Just run ‘admin > emonPi Update’ in local Emoncms to pull in the changes*