WIP: one ./MistServer binary that contains everything

[iameli]

Terrible code. Proof-of-concept only. Doesn't work yet. But it does make one binary that boots a few things! Build the new ninja MistServer target to try it out.

ninja MistServer && ./MistServer -g 8 -c ../config.json

Notes:

• This is one binary embedding MistController MistOutHLS MistOutHTTP MistOutRTMP MistInBuffer MistSession. So far only RTMP input and output work, HTTP is busted. Capabilities discovery is presently limited to some hardcoded JSON strings; you'd probably want to do codegen on that so capabilities can just be hardcoded at compile time.
• I've had to go through a few different code paths that all call execvp themselves to prepend Util::getMyPath() + "MistServer". I assume the right path here would be to refactor all of those calls to use the same helper in procs.h so that can just be hardcoded/IFDEF'd in one place.
• Everything other than the ninja MistServer target is broken on that branch, so there's obviously quite a bit of work to do on setting things up so that they can all be individual modules or one shared thing.