Merge pull request #3 from piotrnar/master

piotrnar's gitian sigs for v0.8.5-OMG3
README.md: Update the zlib download link
wtogami's gitian.sigs.omg for 0.8.5-OMG6
wtogami's gitian.sigs.omg for v0.8.5-OMG8
piotrnar's gitian sigs for v0.8.5-OMG10