go-lang-plugin-org/go-lang-idea-plugin — pull request #658 by dlsniper (2014-03-15 11:36:27+00:00)
Title: Improved GOPATH support (fixes #458)

It won't be per-project but per IDE instance as I don't plan to change the GO SDK from project to project.
If people really have different GOPATHs per project then they should contribute or wait to be fixed.