Fix some memory leaks in parse_avc.c and mkmux.c
Fix another leaks in htsp_server.c (_very_ _VERY_ _BAD_)
Fix the subscription_done() call

The subscription_unsubscribe() must be called from the upper layer (like dvr).
The sbuf allocation cleanups

This is an attempt to fix the nonoptimal memory allocations. The old
code tries to allocate new chunks based on maximum packet value, but
the streams contain mostly short chunks. Also, in some cases, we know
the fixed sbuf size, so use it.
Merge remote-tracking branch 'origin/pr/343'
Merge remote-tracking branch 'origin/pr/344'
service_mapper: fixes problems with saves when updating from services tab

Fixes #1999