started support for generating source maps (WIP)

plugged in @fitzgen's source-map library

tmp/test-maps.js

@@ -0,0 +1,39 @@
+#! /usr/bin/env node
+
+var sys = require("util");
+var fs = require("fs");
+
+var UglifyJS = require("../tools/node");
+
+var files = process.argv.slice(2);
+var map = UglifyJS.SourceMap();
+var output = UglifyJS.OutputStream({
+    beautify   : false,
+    source_map : map
+});
+
+function do_file(file) {
+    var code = fs.readFileSync(file, "utf8");
+
+    // parse
+    var ast = UglifyJS.parse(code);
+
+    // mangle
+    ast.figure_out_scope();
+    ast.mangle_names();
+
+    // compress
+    var compressor = UglifyJS.Compressor();
+    ast.squeeze(compressor);
+
+    // generate source into the output stream
+    // first reset the current file name in the source map.
+    map.set_source(file);
+    ast.print(output);
+};
+
+files.forEach(do_file);
+
+fs.writeFileSync("/tmp/source-map.json", map, "utf8");
+
+sys.print(output);