Allow ":" in auth string for redis.irstack.com

Because Iris Couch requires an AUTH command in the format your_hostname.redis.irstack.com:your_password, we need to not strip the part before the colon in that case.
Update README.md

Removed `sudo` on brew install lines
Remove ":" popping from redis auth strings.

Because Iris Couch requires an AUTH command in the format your_hostname.redis.irstack.com:your_password, we need to not strip the part before the colon in that case. Since we don't really need it in any case (just don't pass the username: in there), it's simplest to not alter the auth string.

https://github.com/josephg/ShareJS/pull/162
Merge branch 'master' of https://github.com/nwinter/ShareJS into nwinter-master
Merge branch 'master' of github.com:josephg/ShareJS
Bump
Merge branch 'master' of git://github.com/josephg/ShareJS