tiff: moved to github

git-svn-id: svn://svn.openwrt.org/openwrt/packages@41779 3c298f89-4303-0410-b956-a3cf2f4a3e73
giflib: moved to github

git-svn-id: svn://svn.openwrt.org/openwrt/packages@41780 3c298f89-4303-0410-b956-a3cf2f4a3e73