Fix broken pg_dump command

Error in the backup command found by Sam on the forums.
See http://www.openmicroscopy.org/community/viewtopic.php?f=5&t=6852
Remove '#sh' from script
Merge pull request #504 from joshmoore/fix-pg-dump

Fix broken pg_dump command
Added section on compound LDAP filters to sysadmin docs
Added section requiring new_users be filtered by the group filter
Fixed underlining typo
Fixed punctuation
Moved LDAP config overview anchor
Merge pull request #508 from hflynn/rebased/dev_4_4/ldap-filters

Ldap filters (rebased onto dev_4_4)