If we are building docs with this release and PREFETCHDISTFILES is defined then download the distfiles for the ports needed to build the docs before we enter the chroot environment.  This is useful since often times releases get in a funk trying to download distfiles in the chroot.
If we are building docs with this release and PREFETCHDISTFILES is defined
then download the distfiles for the ports needed to build the docs before
we enter the chroot environment.  This is useful since often times releases
get in a funk trying to download distfiles in the chroot.

Approved by:	re (murray, bmah)
MFC after:	5 days

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