Update Perl to 5.18.4, fix gcc 4.9 build issue
20141003 uses fewer intermediates then 20141002

See https://github.com/docker-library/official-images/pull/238#issuecomment-57829153
for more comments
Merge pull request #238 from PeterMartini/release/r20141002.0

Update Perl to 5.18.4, fix gcc 4.9 build issue