Clean up EXTRACT_ONLY logic a bit.  Instead of branching in the do-extract target depending on defined(EXTRACT_ONLY) or not, simply set EXTRACT_ONLY ?= ${DISTFILES} and always use ${EXTRACT_ONLY} as the extraction list.
Clean up EXTRACT_ONLY logic a bit.  Instead of branching in the
do-extract target depending on defined(EXTRACT_ONLY) or not, simply
set EXTRACT_ONLY ?= ${DISTFILES} and always use ${EXTRACT_ONLY} as
the extraction list.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase