Rewrite instrument startup scripts to be in python (platform independent)

start_inst.bat (and other files it calls) are windows specific. To start IBEX on Linux would require a similar set of *.sh files. It is probably more sensible to change such startup scripts to be in python so they are both platform independent and can also incorporate some/better error handling. This will be a useful change for any facility that might want to run IBEX on Linux.

ESS will be looking at this