This should make those Macbooks run a bit faster...

Adding -XX:+UseConcMarkSweepGC  &&  -XX:+CMSIncrementalMode for dev machines and teamcity agents.

It is recommended you use  -XX:+CMSIncrementalMode if you hae 1 or 2 CPUs (like your macbook or an EC2 box). Want to try it out here before running it on our EC2 boxes.
Fixed key...
Merge pull request #1291 from guardian/sbt-script

This should make those Macbooks run a bit faster...