Exclude node_modules from Watch task

Reasons: 
  * Causes: 2013-06-02 02:53 node[77377] (CarbonCore.framework) FSEventStreamStart: register_with_server: ERROR: f2d_register_rpc() => (null) (-21)
  * Uses far too much memory.
Merge pull request #4 from distracteddev/patch-2

Exclude node_modules from Watch task