lavf: more correct printf format specifiers
configure: Document --pkg-config option
doc: Add section about AviSynth support

Signed-off-by: Diego Biurrun <diego@biurrun.de>
Merge commit 'd92024f18fa3d69937cb2575f3a8bf973df02430'

* commit 'd92024f18fa3d69937cb2575f3a8bf973df02430':
  lavf: more correct printf format specifiers

Conflicts:
	libavformat/asfdec.c
	libavformat/cafdec.c
	libavformat/dxa.c
	libavformat/framecrcenc.c
	libavformat/hnm.c
	libavformat/iff.c
	libavformat/mov.c
	libavformat/mxfdec.c
	libavformat/rmdec.c
	libavformat/rpl.c
	libavformat/smacker.c
	libavformat/xmv.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '5926603ad65e5fd4fefe8f0d72c381059f71cd59'

* commit '5926603ad65e5fd4fefe8f0d72c381059f71cd59':
  configure: Document --pkg-config option

Conflicts:
	configure

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  doc: Add section about AviSynth support

Conflicts:
	doc/general.texi

Merged-by: Michael Niedermayer <michaelni@gmx.at>
ffplay: display information on stream cycling

Reviewed-by: Marton Balint <cus@passwd.hu>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>