Try to better detect go path on homebrew installs (fix #385)

I'm not even sure if it's working properly but it seems to still work on everything, which is good.
Also, seem that Homebrew is now supported properly so....

Can anyone please test this before merging?

Compiled under ``` 385.jar ``` here: https://www.dropbox.com/sh/kzcmavr2cmqqdqw/j8wjp8SdNH