metadata: add libavcodec > 54 compatibility

libavcodec55 brings some API changes, including CodecID => AVCodecID.
Add a compatibility wrapper so we can build with libavcodec >= 55.
portability: add support for Illumos

This still won't work on older Solaris systems, but modern Illumos
at least should build and run now.
metadata: more libav10 compatibility changes

Add a couple more compatibility wrappers.
metadata: get embedded cover art from video files using libavformat

Newer version of libavformat can grab cover art, so we'll go ahead
and use it.  We also need to make sure we don't confuse cover art
with a normal video stream.
metadata: get rid of some unnecessary mallocs
clients: remove FLAG_SAMSUNG_DCM10 capability

I'm not entirely sure what this flag enables.  But there are reports
that is breaks browsing on Samsung Series F TV's.  So we'll have to
disable for now, until that gets sorted out by people who actually
have Samsung TV's.
clients: add NetFront Living Connect support

Add subtitle support for NetFront™ Living Connect middleware-based
clients.  These appear to include devices from Panasonic, Philips,
Vizio, Sony, and probably more.
Wrap up version 1.1.3.
clients: restructure client cache
process: associate open connections with clients
metadata: support 64-bit time_t

OpenBSD moved all machine architectures to long long time_t in the last
release which triggered a crash in minidlna's scanner on 32-bit systems.

Reported-by: Stuart Henderson
Fixes for client cache restructuring.
upnpsoap: factor out ObjecID translation into a separate function.
upnpsoap: factor out some duplicated code.
containers: add magic container infrastructure

Add support for dynamic containers, with enough flexibility to also
replace our existing container ID replacement functionality.
tagutils-aac: fix bad null termination

SF bug #244, patch #119
Stub out NLS function.
upnphttp: declare a couple functions static
upnphttp: fix requests for the last byte of a file

Philips TV's apparently do this with MKV files (SF bug #180).
Update NEWS.