gnu: icecat: Update to 31.8.0-gnu1.
* gnu/packages/patches/icecat-enable-acceleration-and-webgl.patch: New file.
* gnu/packages/patches/icecat-CVE-2015-2722-pt1.patch,
gnu/packages/patches/icecat-CVE-2015-2722-pt2.patch,
gnu/packages/patches/icecat-CVE-2015-2724-pt1.patch,
gnu/packages/patches/icecat-CVE-2015-2724-pt2.patch,
gnu/packages/patches/icecat-CVE-2015-2724-pt3.patch,
gnu/packages/patches/icecat-CVE-2015-2724-pt4.patch,
gnu/packages/patches/icecat-CVE-2015-2728-pt1.patch,
gnu/packages/patches/icecat-CVE-2015-2728-pt2.patch,
gnu/packages/patches/icecat-CVE-2015-2733-pt1.patch,
gnu/packages/patches/icecat-CVE-2015-2733-pt2.patch,
gnu/packages/patches/icecat-CVE-2015-2735.patch,
gnu/packages/patches/icecat-CVE-2015-2736.patch,
gnu/packages/patches/icecat-CVE-2015-2738.patch,
gnu/packages/patches/icecat-CVE-2015-2739.patch,
gnu/packages/patches/icecat-CVE-2015-2740.patch,
gnu/packages/patches/icecat-CVE-2015-2743.patch: Remove files.
* gnu-system.am (dist_patch_DATA): Remove them, and add the new file.
* gnu/packages/gnuzilla.scm (icecat): Update to 31.8.0-gnu1. Remove the
outdated patches and add the new one.