Use esprima-fb from NPM by default (override via options.esprima).

Closes #105.

lib/options.js

@@ -2,7 +2,7 @@ var defaults = {
     // If you want to use a different branch of esprima, or any other
     // module that supports a .parse function, pass that module object to
     // recast.parse as options.esprima.
-    esprima: require("esprima"),
+    esprima: require("esprima-fb"),
 
     // Number of spaces the pretty-printer should use per tab for
     // indentation. If you do not pass this option explicitly, it will be

package.json

@@ -25,7 +25,7 @@
     "debug": "node ./node_modules/mocha/bin/mocha --debug-brk --reporter spec"
   },
   "dependencies": {
-    "esprima": "git+https://github.com/ariya/esprima.git#harmony",
+    "esprima-fb": "~5001.1.0-dev-harmony-fb",
     "source-map": "0.1.32",
     "private": "~0.1.5",
     "cls": "~0.1.3",

test/parens.js

@@ -1,5 +1,5 @@
 var assert = require("assert");
-var esprima = require("esprima");
+var esprima = require("esprima-fb");
 var parse = require("../lib/parser").parse;
 var Printer = require("../lib/printer").Printer;
 var NodePath = require("ast-types").NodePath;