Merge remote-tracking branch 'qatar/release/0.5' into release/0.5

* qatar/release/0.5:
  Bump version number for 0.5.8 release.
  Release notes and changelog for 0.5.7
  vqavideo: return error if image size is not a multiple of block size
  motionpixels: Clip YUV values after applying a gradient.
  mjpegbdec: Fix overflow in SOS.
  atrac3: Fix crash in tonal component decoding.
  dv: Fix small stack overread related to CVE-2011-3929 and CVE-2011-3936.
  dv: Fix null pointer dereference due to ach=0
  dv: check stype
  nsvdec: Propagate errors
  nsvdec: Be more careful with av_malloc().
  nsvdec: Fix use of uninitialized streams.


Merged-by: Michael Niedermayer <>