Added generative testing for AST conversions.

package.json

@@ -1,6 +1,6 @@
 {
-    "name": "uglify-js",
-    "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
+  "name": "uglify-js",
+  "description": "JavaScript parser, mangler/compressor and beautifier toolkit",
     "homepage": "http://lisperator.net/uglifyjs",
     "main": "tools/node.js",
     "version": "2.4.15",
@@ -17,9 +17,15 @@
     "dependencies": {
         "async"      : "~0.2.6",
         "source-map" : "0.1.34",
-        "optimist"   : "~0.3.5",
+        "optimist": "~0.3.5",
         "uglify-to-browserify": "~1.0.0"
     },
+    "devDependencies": {
+        "acorn": "~0.6.0",
+        "escodegen": "~1.3.3",
+        "esfuzz": "~0.3.1",
+        "estraverse": "~1.5.1"
+    },
     "browserify": {
         "transform": [ "uglify-to-browserify" ]
     },