Use full path for getRequire

Hello I was trying to run `condense` on https://github.com/metapolator/metapolator . I got an error:

    fs.js:432
      return binding.open(pathModule._makeLong(path), stringToFlags(flags), mode);
                     ^
    Error: ENOENT, no such file or directory '/home/rrt/.local/var/repo/metapolator-rrthomas/app/lib/gonzales.cssp.node.js'

I am using a command line something like this:

    condense --plugin requirejs='{"paths": { "metapolator": "./", "gonzales": "npm_converted/gonzales/lib" }}' models/CPS/elements/GenericCPSNode.js 

The `require` statement that causes the problem is:

    exports.srcToCSSP = require('./gonzales.cssp.node').srcToCSSP;

As far as I can see, the problem is that in the `getRequire` function in the `requirejs` plugin, the call to `getInterface` does not prepend the current directory. The change in this commit does so (though, apologies, I have no idea if this change uses the correct data source or is in the correct place: I am very new to Tern), and with this change, the analysis completes fine.