Fixed typo in comment.
Dropped GlobalindexMaintenanceView.

The view is not used at the moment and has to be written complety.
Currently it's not definitely that we use a view for Globalindex Maintenance
Jobs. Therefore we drop it.
Merge cleanup.
Rework task accept: use current orgunit/AdminUnit instead of current client.
Rework `remote_request` and `remote_json_request`.

Use AdminUnit.id instead of client_id.
Rename client_id to admin_unit_id.
Use admin units in close task form of information tasks.
Use admin units when updating ogds sync timestamp.
Fix wrong method, use format.
Use admin unit when closing predecessor/successor tasks.
Use admin unit in state syncer.
Rename client_id to target_admin_unit_id for response transporter.
remote_request: fixed check if it's a target admin_unit.
Pyflakes.
Update forwarding transition controller.

Changed condition for `accept` and `assign to dossier` to work with
admin_units/org_units.
Use admin_unit_id for cross AdminUnit request authentication.

See ogds.base tentacle plugin.
Refuse forwarding form: Use admin_unit_id for cross AdminUnit requests.
Use current admin_unit's id when pushing wizard-data to the remote storage.
Fixed rolessource section: `OrgUnit.users_group` is a method not a property.
Add `SchemaMigration` base class for sql-database migrations.