Protobuf Dependency Management

[moloch--]

the packaged 6github.com.zip containing the protobuf dep was not matching the protoc-gen-go lib I had on my system, and building the agent always failed with the following error:

undefined: proto.ProtoPackageIsVersion3

I had to repackage the dep with a fresher version of the protobuf lib.

[Eriner]

As a potential fix, check the retcode in the makefile and conditionally execute go get (as done with #4)?

[moloch--]

It's a little tricker than that, we basically need to add it to the go-assets.sh script, this dependency get's zip'd and shipped with the server binary --along with all the Go compiler tool chain, which is how the server is able to dynamically compile new binaries with it's own certs.