minimal build all option without XRFapp

[TomQD-94]

When runnning up servers at QD we don't actually use the XRFapp part of the build. I find myself commenting out the xrf components in the 'all' command

elif cmd == 'all': xrfapp_proc = mp.Process(target=install_xrfapp, args=(nelem,)) xrfapp_proc.start() extract_sources() create_buildscript(nelem=nelem) configure_release() build() xrfapp_proc.join()

Would it be possible to add a new option for a minimal install without these components. Saves me commenting out or running script multiple times

[newville]

@TomQD-94 Sure, we can make that "opt in".