Add private replacements for deprecated functions such as
g_mutex_new(), g_mutex_free(), g_cond_new() etc., mostly
to avoid the deprecation warnings. We can't change most of
these in 0.10 because they're part of our API and ABI.
... in the extent that a non-waiting pad (so indicated by newsegment)
turns out to provide the best buffer, which is then forced to waiting
for book-keeping purposes, but that should only be temporary.
See bug #415754.
This handles muxing of sparse/subtitle streams and has
lots of cleanup. Still missing is special support for
live streams but this can be added later without breaking
API/ABI.
Based on the version from the videomixer plugin.
https://bugzilla.gnome.org/show_bug.cgi?id=415754
