Make utility's external imports optional. Done with #1778 and #1200.
Make utility's external imports optional. Done with #1778 and #1200.

Utility is kind of a catch-all. Not all uses of it (particularly when it
is being used to test plugins in a separate container from PSC) will use all
its capabilities, so there's no need to force those uses to resolve all its
many dependencies.

git-svn-id: 4b387fe5ada7764508e2ca96c335714e4c1692c6@7068 0d517254-b314-0410-acde-c619094fa49f

NUBIC/psc-mirror,NUBIC/psc-mirror,NUBIC/psc-mirror,NUBIC/psc-mirror