demux: asf: check only active tracks within video/audio

or pcr update could never happen
demux: asf: re-preroll on seek

Should avoid hiccups after seek
demux: asf: use VLC_TS_0 in debug
demux: asf: use send_time as preroll

Otherwise would buffer a preroll + min track delay
dcp: ignore prefixes in XML nodes

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>
Contribs: add asdcplib

Not activated by default, because of probable hard OpenSSL dependency
Note that expat is not mandatory to build it...

ASDCPlib in itself is BSD 3-clause
video_chroma/swscale.c: Fixup commit eae2f440af1d7e79019adc4da5f871d0592d9f91
Contribs: asdcplib, enable freedist and change Win32 flags
integer: simplify
araw: filter out non-finite floating point samples

The input is not neessarily trusted. Better safe than sorry.
demux: asf: fix preroll deadline
demux: asf: set preroll point after indexless seek
demux: asf: fix PCR reset call
demux: asf: add TS_0 to debug info
demux: asf: remove assertion

always fails on non mms
demux: asf: add workaround for audio es delay
macosx: move re-useable code from menu to core interaction object
macosx: clean-up string utility
macosx: fix warning
input: fix warning