Add XMLRPC sync, vhost location custom settings

- Typo: Lots of typo fixes and re-indenting
- XMLRPC: Added actual code for XMLRPC (not 100% functional, synchronization succeeds but remote reload fails)
- VirtualHost: Added custom settings for Locations (for SSLRequire & such ; edit screen is included, but I haven't found a way to generate proper links to <PFSENSE>/apache_edit_virtualhost_location.php?virtualhost_id=X&backend_id=Y with the existing GUI)
- Settings: Use interfaces instead of manual input IP address