[Packager] Windows support for Packager - Blacklist changes

Summary:
Another Pull Request implementing the changes in issue #468 - Enabled Packager to run on Windows
This change relates to the blacklist fixes. It includes the path conversion for blacklist and changes to the default watched directory.  It has no impact on Mac OSX.
Closes #893
Github Author: Joe Wood <joewood>

Test Plan: Imported from GitHub, without a `Test Plan:` line.

packager/blacklist.js

@@ -8,6 +8,8 @@
  */
 'use strict';
 
+var path = require('path');
+
 // Don't forget to everything listed here to `testConfig.json`
 // modulePathIgnorePatterns.
 var sharedBlacklist = [
@@ -39,7 +41,9 @@ var platformBlacklists = {
 };
 
 function escapeRegExp(str) {
-  return str.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, '\\$&');
+  var escaped = str.replace(/[\-\[\]\{\}\(\)\*\+\?\.\\\^\$\|]/g, '\\$&');
+  // convert the '/' into an escaped local file separator
+  return escaped.replace(/\//g,'\\' + path.sep);
 }
 
 function blacklist(platform, additionalBlacklist) {

packager/packager.js

@@ -69,8 +69,9 @@ if (options.projectRoots) {
     options.projectRoots = options.projectRoots.split(',');
   }
 } else {
-  if (__dirname.match(/node_modules\/react-native\/packager$/)) {
-    // packager is running from node_modules of another project
+  // match on either path separator
+  if (__dirname.match(/node_modules[\/\\]react-native[\/\\]packager$/)) {
+     // packager is running from node_modules of another project
     options.projectRoots = [path.resolve(__dirname, '../../..')];
   } else if (__dirname.match(/Pods\/React\/packager$/)) {
     // packager is running from node_modules of another project
@@ -97,7 +98,8 @@ if (options.assetRoots) {
     });
   }
 } else {
-  if (__dirname.match(/node_modules\/react-native\/packager$/)) {
+  // match on either path separator
+  if (__dirname.match(/node_modules[\/\\]react-native[\/\\]packager$/)) {
     options.assetRoots = [path.resolve(__dirname, '../../..')];
   } else if (__dirname.match(/Pods\/React\/packager$/)) {
     options.assetRoots = [path.resolve(__dirname, '../../..')];