DO NOT MERGE - OC.de with okapi - first draft

Implemented access to oc.de with OKAPI and OAuth for getting found status and filtering.
Added a checkbox to switch off gc.com
Small tweak to get twitter running for me (will do a separate pull for this anyway)

Error-handling and polishing (and logging) is missing. Some strings in OAuth still say 'twitter' hardcoded.

Comments welcome!