Merge commit 'f90729699db9ede2bef2b28000f1795dab1b8996'

* commit 'f90729699db9ede2bef2b28000f1795dab1b8996':
  mov: Do not group tracks if more than one is enabled per type

Conflicts:
	libavformat/movenc.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/movenc.h

@@ -176,6 +176,8 @@ typedef struct MOVMuxContext {
     int64_t reserved_moov_pos;
 
     char *major_brand;
+
+    int per_stream_grouping;
 } MOVMuxContext;
 
 #define FF_MOV_FLAG_RTP_HINT 1