Nextcloud integration

[longsleep]

Similar to the Nextcloud issue https://github.com/nextcloud/server/issues/828 this issue tries to break down Nextcloud integration in work packages.

• [ ] Remove top bar, integrate call control with notifications
• [ ] Bootstrap 3 theme for buttons, headers and input which matches the Nextcloud style
• [ ] Further Nextcloud style harmonizing
• [x] Make Spreed.ME settings available as Nextcloud settings – #39
• [ ] Client and server side session resumption and keep-alive, including client-side and server-side queue
• [ ] Call resumption support after navigation (auto hold / resume)
• [ ] Web client build target to support Nextcloud without Go backend. / maybe split out the web client
• [ ] Define and implement Web client API for Nextcloud UI integration from other apps

Please comment if i missed something.

[JSoko]

Features witch would be also nice to have in Spreed.ME under Nextcloud too:

• [x] Locking a room https://github.com/strukturag/spreed-webrtc/issues/239
• [ ] session recording https://github.com/strukturag/spreed-webrtc/issues/331
• [ ] Using Spreed Desktop for invited People who are not Nextcloud Users https://github.com/strukturag/spreed-webrtc/issues/342
• [ ] integration of sip voip https://github.com/strukturag/spreed-webrtc/issues/297

[enoch85]

• [ ] Make it possible to generate a new Shared Secret and SpreedMe WebRTC config via CLI

This is to make it possible to fully automate the install in the Nextcloud VM.

[leonklingele]

We now have https://github.com/nextcloud/spreed