This commit adds the following:
- Storage of server groups in the configuration database
- Creation of a default server group on in the database
- A mechanism for plugging in treeview node types
- A node type for server groups with:
- Treeview display
- Custom per-node javascript implementing a menu option/dialogue to add new groups
- Custom per-node CSS to style the treeview node
- JSON formatted data in response to AJAX requests, including:
- Success/failure indication
- Error message
- Extra info (e.g. stack trace)
- The original request data
- Additional return data, e.g. node ID and label etc.
Modules may now include functions that return lists of menu items
that will be included on the main browser window menu. While we're
at it, move the test views into a separate module.
