Main10 / RExt support

Changes:

• Added support for Main10 / RExt streams (i.e. chroma formats 422, 440 and bit depths > 8 bits per pixel) with libde265 1.0.0 or newer.
• Explicitly link against -audio and -tag libraries if Matroska/MP4 part is enabled.

GStreamer 1.4 support

Changes:

• support building against GStreamer 1.4
• fixed memory leak if decoder could not be flushed
• make number of threads configurable

MP4 support

Changes:

• Decode NAL blocks in extra data. Fixes broken decoding for some files.
• Added patched isomp4 decoder with support for HEVC video.
• Register patched demuxers with custom name to prevent overwriting by original demuxer.

Direct rendering / libde265 0.7

Changes:

• requires libde265 0.7
• support direct rendering with GStreamer 1.0 and above to avoid unnecessary memory copying
• minor changes / bugfixes

MPEG-TS

Changes:

• added decoding of HEVC/H.265 in MPEG-TS (if supported by underlying GStreamer framework)
• improved detection of packetized / raw HEVC streams
• improved handling of excessive fps values
• use "common" submodule from GStreamer to check indentation settings

v0.1.7

Tag release 0.1.7