simplified isLocal() method to determine if mxCuBE runs locally or if it
is started from a remote host (detects Remote Access role: either Server
or Client).
The detection is based on the DISPLAY environment variable;
if DISPLAY is set to a particular host, Server privileges will be granted
only if it corresponds to the fully qualified domain name of the host
running mxCuBE.
Merge branch 'master' of github.com:mxcube/HardwareRepository
backward compatibility for get_value