Updates the layout.jade to use dynamic linker

Updates the layout.jade to use dynamic linker (via // SCRIPTS tags ).
Corrects non-linker javascript tag url.
Removes unused javascript tags.

Doublecheck this, please...  I verified in the ejs template that you no longer use the socket.io.js or example.js in that template either, so I think it's safe to leave these out here.  In any case, these aren't in assets anymore (and socket.io.js is minified in sails.io.js as well, it seems).

Should fix balderdashy/sails#1754