imagemagick - security update

This updates fixes many vulnerabilities in imagemagick: Various memory
handling problems and cases of missing or incomplete input sanitising
may result in denial of service or the execution of arbitrary code if
malformed TIFF, WPG, RLE, RAW, PSD, Sun, PICT, VIFF, HDR, Meta, Quantum,
PDB, DDS, DCM, EXIF, RGF or BMP files are processed.

For the stable distribution (jessie), these problems have been fixed in
version 8:6.8.9.9-5+deb8u4.

For the unstable distribution (sid), these problems will be fixed soon.

We recommend that you upgrade your imagemagick packages.