Docker: fix builds

[Thann]

Also: Dockerhub should be updated to build images off of the development branch, OR master should get bumped. I think having both :dev & :stable images is the best solution.

[tynes]

Good calls on the multiple images that follow the two main branches. Testing this now

[tynes]

I pushed up some changes to this PR. I changed to building the local dockerfiles by default since our remote ones need to be set up and automated properly. I am installing unbound so that handshake can build properly and fixed a configuration problem with securityc.

If you docker-compose up, it should just work if you go to localhost, besides the websocket that tries to connect over ws instead of wss

[bucko13]

I added some extra comments around the BPANEL_PLUGINS variable in the compose file since I could see this causing some confusion if someone checks their config.js and it doesn't match their actual build. I also set connection-manager as one of the default BPANEL_PLUGINS.

I also created some more tags in docker hub as per the comments and have the compose pull from the :dev image. Ideally this will pull from :stable, but while we still work out the kinks of the plugin versioning, this is probably the better approach.

Unless there are other thoughts or comments, I'll merge this in and we can confirm that the tags work (and should be ready for the release).

For reference, here are the build tags I setup in docker hub:

[bucko13]

dev builds were failing because of an empty plugins/local folder (the index gets built with a script). 15fbf29 adds a gitkeep to avoid the error.