compress 'stitched' code and cache as file

index.js

package.compile(function (err, source) {
    var jsp = require("uglify-js").parser;
    var pro = require("uglify-js").uglify;
    var ast = jsp.parse(source); // parse code and get the initial AST
    ast = pro.ast_mangle(ast); // get a new AST with mangled names
    ast = pro.ast_squeeze(ast); // get an AST with compression optimizations
    var final_code = pro.gen_code(ast); // compressed code here
	  fs.writeFile(__dirname + '/public/scripts/application.js', final_code, function (err) {
	    if (err) throw err;
	    util.puts('Compiled application.js');
	  })
	});