Bug 5614: Organize 'patron' system preferences

Bug 5614: Organize 'patron' system preferences

Until now, there was only "General" and "Privacy". This patch
breaks the "General" prefs up into multiple sections.

To test:
- Go to Administration > Patrons
- Verify the current state of things
- Apply patch
- Reload patch
- Verify headings make sense and groups make sense as well

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>