GOPATH now works during first build and DEPENDS variables fixed.

Hi Aki,

I am very happy you have written this ROS/GO binding.  I worked on something similar myself last year but didn't have time to make much progress.  Looks like you have done great!

This pull request makes your whole set of rosgo repositories build for me out of the box, which they did not initially.

If there is any part of it that you would like help with, please let me know.  I will be using rosgo in my spare time, and I am happy to help with the infrastructure as well.