Add stage support to bsd.cran.mk and convert all ports defining USE_R_MOD to support staging. Since this patch converts all affected ports make the use of NO_STAGE produce an error.
This patch has been tested on my system by building all affected ports - without issue - however I would like a more thorough test of this patch.
Fix: Patch attached with submission follows:
take for exp-run
back to dbn, no new failures. portmgr approval for sweeping commit.