busybox: enable readlink by default, it is used by various scripts

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/branches/attitude_adjustment@37896 3c298f89-4303-0410-b956-a3cf2f4a3e73
AA: odhcp6c: more compatibility fixes

git-svn-id: svn://svn.openwrt.org/openwrt/branches/attitude_adjustment@37908 3c298f89-4303-0410-b956-a3cf2f4a3e73
Merge remote branch 'aa/master'