Change default search scope to ONELEVEL
Allow setting of LDAP search scope in config.
Add automount commands:
- Define automount and automap config sections
- make automount map sub-command work with nisMap objects
- Use 'extendbase' to allow nisObjects to be parented by a nisMap object (POC for review?)
Tidy up some code
Rename 'extendbase' to more correct 'rdn'
Use empty string instead of None to avoid 'str(None)' occurring