Don't base share-without-code urls at root.  We are relying on the browser here to relativize based on the document path. This should work in everything after IE6 (which is now ancient)
Don't base share-without-code urls at root.  We are relying
on the browser here to relativize based on the document path.
This should work in everything after IE6 (which is now
ancient)

Closes #951

alphalambda/codeworld,google/codeworld,google/codeworld,google/codeworld,alphalambda/codeworld,alphalambda/codeworld