Put in place the standard mechanism for store.
Load the store when it is needed.

Rename get_json_store → get_jsonstore.
Add some protection.
For the time being the grid use a complete configuration for a store not only it id string.

All action return a dictionary containing the ROOT key with the id of the modified/update/delete row.

Raise an HTTP exception when a script does not exist.

Mainly use to build the index and debug controllers.

The service DbSvc and CfgSvc use now the Ext.Direct protocol.

To be used with the Ext;direct ptotocole.

It implement a new debug policy based on the attributes self.debug.

Deploy it in all DbSvc method.
remove the dependence to basesvc.
Use the new helper function as_list