Ontology tool: add default workspace setting to user profile
Ontology tool: respect user profile workspace setting
Classification editor: only show editing tools if user has can_annotate permission
Classification editor: pass project and workspace objects to templates

Before, only IDs where passed. This change is made to allow easier
permissiorn checks in within the templates.
Classification editor: use RequestContext for templates

This gives the templates access to request parameters like the current
user.
Classification editor: check permissions in templates

All classification templates now render only editing/changing options
if the current user has the 'can_annotate' permission for the current
project and the current workspace.

In the front-end the attachment of one call-back method had to be
adjusted. It will now only be used, if the target container is actually
present (which it might be not due to limited permissions).