Prevent Windows from watching root path on Windows due to case sensit…

…ive matching. Fixes ef4#17

lib/caching-browserify.js

@@ -145,12 +145,17 @@ module.exports = CoreObject.extend({
   watchNodeModules: function(readTree) {
     var self = this;
     return mapSeries(Object.keys(self._watchModules), function(dir){
-      if (dir !== self.root){
+      if (self.normalizePath(dir) !== self.normalizePath(self.root)){
         return readTree(dir);
       }
     });
   },
 
+  // Changes path drive-letter to lowercase for Windows
+  normalizePath: function(path) {
+    return path.match(/^[a-z]:\\/i) ? path.charAt(0).toLowerCase() + path.slice(1) : path;
+  },
+
   // Due to the way CJS dependencies work, the appearance of a new
   // file in our input trees doesn't invalidate our cache -- because
   // unless one of the existing files changes, nobody depends on the