LP 1768715: Add pingest.pl to Evergreen.

LP 1768715: Add pingest.pl to Evergreen.

Add Open-ILS/src/support-script/pingest.pl to do ingests in parallel.
See release notes for details.

NOTE: This and subsequent commits were added from a branch that
preserves the history of the repository from which pingest.pl was
copied.  The dates on these commits represent when the code was added
or modified in the source repository.  They do not reflect when the
code was added to Evergreen.

Also, pingest.pl predates this commit.  The date on this commit was
when the source repository was split into separate directories for SQL
and Perl scripts.

Signed-off-by: Jason Stephenson <jstephenson@mvlc.org>