Merge remote-tracking branch 'qatar/master'

* qatar/master:
  doxygen: Consistently use '@' instead of '\' for Doxygen markup.
  Use av_printf_format to check the usage of printf style functions
  Add av_printf_format, for marking printf style format strings and their parameters
  ARM: enable thumb for Cortex-M* CPUs
  nsvdec: Propagate error values instead of returning 0 in nsv_read_header().
  build: remove SRC_PATH_BARE variable
  build: move basic rules and variables to main Makefile
  build: move special targets to end of main Makefile
  lavdev: improve feedback in case of invalid frame rate/size
  vfwcap: prefer "framerate_q" over "fps" in vfw_read_header()
  v4l2: prefer "framerate_q" over "fps" in v4l2_set_parameters()
  fbdev: prefer "framerate_q" over "fps" in device context
  bktr: prefer "framerate" over "fps" for grab_read_header()
  ALSA: implement channel layout for playback.
  alsa: support unsigned variants of already supported signed formats.
  alsa: add support for more formats.
  ARM: allow building in Thumb2 mode

Conflicts:
	common.mak
	doc/APIchanges
	libavcodec/vdpau.h
	libavdevice/alsa-audio-common.c
	libavdevice/fbdev.c
	libavdevice/libdc1394.c
	libavutil/avutil.h

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

libavformat/internal.h

@@ -106,7 +106,7 @@ uint64_t ff_ntp_time(void);
  */
 int ff_url_join(char *str, int size, const char *proto,
                 const char *authorization, const char *hostname,
-                int port, const char *fmt, ...);
+                int port, const char *fmt, ...) av_printf_format(7, 8);
 
 /**
  * Append the media-specific SDP fragment for the media stream c