Support gopath packages without dots in name
Support gopath packages without dots in name

Currently if you have a package in GOPATH that does not contain
dots in name and imports other packages in GOPATH that do contain
dots in name, you get:

non-standard import "github.com/aaa/bbb" in standard package "ccc"

This change maintains proper distinction between GOPATH and GOROOT
packages to fix the issue.

Update #120

octo/go-fuzz,dvyukov/go-fuzz,octo/go-fuzz,dvyukov/go-fuzz