Move duckpan.js into DuckPAN sharedir

Currently DuckPAN makes a request for the file `spice2_duckpan_compile.js` which is a small JS script created for DuckPAN to compile the Spice templates and now to properly display Goodies.

There is no need for this file to be requested over the web, and seeing as DuckPAN is the only thing using it, I figure it might as well live in the DuckPAN repo.