Fix to support additional node in megamcib, build changes for golang.

* `megamcib` now builds 2 debs
- megamcib.deb, megamcibn.deb

2 iso's
- trusty_megam.iso (can be burned in an usb)
- trusty_megamnode.iso (its only an iso, can't be burned in a usb).

* no environment variable is needed for golang builds, we use the `GOPATH` itself.