Eliminated extra /p4/Version file.
The standard for determining the SDP version for 2020.1 and forward
will be the file /p4/sdp/Version. This is more clear. Job SDP-564
evolved slightly (per DevNotes in the job). The goal remains the same,
to standardize the method of determining the SDP version for SDP
It was deemed that having an extra copy in /p4/Version will not help
with that, and instead would introduce more failure modes and
possibilities for out-of-sync files.
This does mean the 'tarball extraction' sdp folder that is symlinked
to from /p4/sdp is now a critical part of the SDP installation. This
is normal and as documented, though there have been cases where
SDP is copied from one machine to another in some incomplete way,
e.g. rysnc of /p4/common but not /hxdepots/sdp and the symlink to it
from /p4/sdp. However, the verify_sdp.sh will catch that form of