OMG a ridiculous commit to overhaul import handler config etc.

- add `MasterView.configurable` concept, `/configure.mako` template
- add new master view for DataSync Threads (needs content)
- tweak view config for DataSync Changes accordingly
- update the Configure DataSync page per `configurable` concept
- add new Configure Import/Export page, per `configurable`
- add basic views for Raw Permissions

tailbone/templates/datasync/changes/index.mako

@@ -3,8 +3,8 @@
 
 <%def name="context_menu_items()">
   ${parent.context_menu_items()}
-  % if master.has_perm('configure'):
-      ${h.link_to("Configure DataSync", url('datasync.configure'))}
+  % if request.has_perm('datasync.list'):
+      <li>${h.link_to("View DataSync Threads", url('datasync'))}</li>
   % endif
 </%def>