DM-1338 may allow to switch Qserv or dependency version using eups, without having to re-configure Qserv (i.e. without any change in QSERV_RUN_DIR).
There may have conditions for this to work. That's why it's reasonable to get some user feedback on DM-1338 before documenting this feature.
Make QSERV_RUN_DIR scripts able to detect qserv install paths using eups
Obsoleted by containerization.