[WIP] Removed integrated MJPEG streamer - Part1

[marcus-oscarsson]

This PR removes the integrated MJPEG streamer and the option USE_EXTERNAL_STREAMER. The later permitted to specify whether the internal streamer or an external streamer (most likely the mxcube video-streamer) was to be used.

With this PR its thus no longer possible to use the internal streamer and one has to rely on i.e video-streamer

As far as we know everybody is today already using the video-streamer mentioned above.

In Part-1 we focus on removing the backend bits, we will follow up with a Part-2 for the front end and possibly a Part-3 with some general improvements.

[fabcor-maxiv]

Maybe we should really start getting into the habit of maintaining a change log. I know we discussed this already in the past but never acted on it (I am as guilty as anyone else here, of course, not blaming anyone). It came back to my mind now, seeing all the backwards-incompatible removals (the clean ups are much appreciated of course).

I guess it is something that needs its own discussion thread rather than this comment. I will try to get to it tomorrow, unless someone else beats me to it.

[marcus-oscarsson]

Actually, we've discussed change logs in the past and I've proposed that we should have one. The overall concuss has however been to not have one. I cant remember how the reasoning when at the moment. I suggest that we re-discuss the topic on our next developers meeting.

Edit: So Ill be all for having one, but as we discussed it before I just want to make sure that its discussed again before we go-ahead.

[marcus-oscarsson]

Actually, I also wanted to bring up the topic of "planned releases" on our next developers meeting. We can perhaps find a good way to make that work for the project.

[marcus-oscarsson]

Judging from our last developer meeting it then seems fine to proceed with this PR.