drivers.py -- added code to run the stop command in background.

Slightly tricky code to see if I can get round the issue with the GUI not updating once "Stop" is pressed
usdriver.py, lakeshore.py, uspec.py -- CCD temperature stuff

Displays CCD temperature in run & telescope section; sets it and related parameters in xml.
globals.py -- defines object to interface to lakeshore temperature controller
slide.py -- small format change