sout: sdi: replace the thread cleanup calls by a canceled boolean
mutex_cleanup_push() and vlc_cleanup_pop() are not available in C++. All we want is to tell the feeder thread to exit when it's idle.
The condition will be triggered when:
- a frame has completed
- the maxdelay to wait before scheduling a new frame has been reached
- the thread cancel has been requested
Also clean vlc_tick_t
usage and allow win32 builds (untested, like the other platforms since we never build it)
Deprecates !306 (closed)