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.
Conflicts:
libavcodec/atrac3.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
