This PR contains:

• User Settings to en/disable DCL
• Key-Handling / Import for the DCL-Interface (currently only Test-ENV on DARC-Side)
• UI-Arrows and Views for DCL
• Upload to DCL (still in progress - testing at $wl_ulr/dcl/dcl_upload)
• Download from DCL (as far as i know, Download happens in a second iteration)
• Arrows for LBA / DCL
• Batchedit for DCL in LBA
• Filter for LBA DCL
• Editing DCL-Status for QSO
• Implement session-less running (for cron)
• Config.php Entry for disabling the feature completly (default) $config['enable_dcl_interface']
• Add migration for cron-manager

For merging it, it requires a few more things, than the mentioned above:

• Provide final URL ( @dg0tm )
• Make DCL-Endpoint performant ( @dg0tm )
• Parsing information from DCL on Upload (perhaps @phl0 )
• Adding MY_DARC_DOK to QSOs based either on Userinput or the results from get_info (at DCL-Model)
• checking the construction-sites marked with "todo" in source
• testing

to be continued...