How do you add an external package to a GoClipse project for Google App Engine?

I've compiled Goauth so that I can use OAuth in my Go Google App Engine project. Where do I put the goauth.a file so that I can both use it in the project, and have it available when deploying to the GAE servers? I can get it working locally if I put it in a subfolder of $GOROOT/pkg, but then it can't be found when compiling at deployment time.

GoClipse sets up a project with lots of folders, I'm not really sure what their purpose is, where should I put goauth.a and how do I import it?

To fix this I ended up including the source for the package in the directory tree for my app, as mentioned in this thread on the google-appengine-go group http://groups.google.com/group/google-appengine-go/browse_thread/thread/1fe745debc678afb

Here is the important part of the thread:

> You may include as many packages as necessary. Packages are imported
> by path relative to the base directory (the one that has your app.yaml
> file), so if you have the following:
>
> helloworld/app.yaml
> helloworld/hello/hello.go // package hello
> helloworld/world/world.go // package world
>
> you can import "world" in hello and import "hello" in world.
>
> If you are including a third-party library, it might look something like this:
>
> helloworld/app.yaml
> helloworld/hello/hello.go // package hello
> helloworld/world/world.go // package world
> helloworld/goprotobuf.googlecode.com/proto/*.go // package proto
>
> Then you can, as normal, import "goprotobuf.googlecode.com/proto".