rebuild the documentation database at install/deinstall time. This means
that:
- PLIST's do not need to call scrollkeeper-{update,rebuilddb} directly;
this is done by a bsd.pkg.install.mk template.
- The share/omf directory is only removed by scrollkeeper, which is the
last package in the dependancy tree.
- PKGREVISION is bumped.
Reviewed by wiz.