umurmur: add support for the new polarssl library

git-svn-id: svn://svn.openwrt.org/openwrt/packages@35413 3c298f89-4303-0410-b956-a3cf2f4a3e73
polarssl,openvpn,openvpn-devel: delete (merged to trunk)

git-svn-id: svn://svn.openwrt.org/openwrt/packages@35414 3c298f89-4303-0410-b956-a3cf2f4a3e73