Resolves issue on OS X Lion where Macvim starts up but unable to windows

I believe this issue is the same issue and/or strongly related to https://github.com/alloy/macvim/issues/68. Explanation for this is likely related to the special "notes" under the build instructions for the upstream macvim repo. See https://github.com/b4winckler/macvim/wiki/Building#how-to-build-macvim

Tested under Lion and Mountain Lion. Works for me (that phrase we all love to hate)

Also, not sure if this is related but worth a mention I guess. "Reveal in File Browser" functionality works for me on both platforms