Restore compability with current release (JSDoc 3.0.1)

The current release, as well as whatever version is currently
bundled in /lib, still has the directory name "rhino_modules". This
change assumes the directory is called "rhino", but falls back to
"rhino_modules" if that directory doesn't exist.
Fixed Windows issues with absolute paths.

JSDoc doesn't seem to like absolute paths on Windows, and as far as
I can see relative paths work just fine.
Merge pull request #5 from pmcelhaney/fix-windows-absolute-path-issue

Fix windows absolute path issue