Add support for dry run -N (--dryrun)
Move --dry-run to 1.3
Add output explaining that repack won't be issued
Move new log output to inside the dryrun block
Add test for --dry-run

This should probably be rewritten to actually check OID on old/new tables so
that we don't accidentally execute repack during a dry run.
Merge branch 'master' into 21_dryrun
Make the 'repacking index ...' message be displayed
for indexes-only repacks (not just when in dry-run mode).