Issue #2976334 by tedbow, Wim Leers, johndevman, tim.plunkett, phenaproxima,...

Issue #2976334 by tedbow, Wim Leers, johndevman, tim.plunkett, phenaproxima, larowlan, samuel.mortenson, Berdir, EclipseGc, johnzzon: Allow Custom blocks to be set as non-reusable adding access restriction based on where it was used