possible sails bug regarding policy chaining

extended description

This illustrates a possible bug in sails. 

Steps to replicate. Submit a form once, then submit it again. The server will break.

This only occurs when using policy chaining, as rolling back the policy chaining (using only one policy per action) seems to resolve the issue.

Steps taken to resolve: I edited /sails/lib/scaffolds/controller.js:133:17 to change `res.json(values)` to `res.send(JSON.stringify(values))`. I did this, as I reasoned that this would avoid writing 'Content-Type : application/json' headers to the response. This changed the behaviour such that it caused the connection to hang on the second POST - a response would never be sent, and the connection would be held open.

I will attempt to create a reduced test case later.

gistfile1.txt

jbeard4@ps16821:~/workspace/testProject$ sails lift
debug: Starting server in /home/jbeard4/workspace/testProject...
verbose: Loading module sails-mysql...
   info  - socket.io started
debug:
debug:
debug:
debug:
debug:                    <|
debug:                     |
debug:                 \\____//
debug: --___---___--___---___--___---___
debug: --___---___--___---___--___---___
debug:
debug: Sails lifted on port 1337 in development mode.
debug:
debug: ( to see your app, visit: http://localhost:1337 )
^[[B^[[B^[[BComparing password with hashed password test $2a$10$U.akKXaJh9Chu2mhg98N1.sXp8tyUMJvpsbS0FPuNGT3yxF2tDyV.
in authenticated
in addCreatedBy
Total Pollens is now 0.64
Total Mold Spores is now 0.208
verbose: Published [object Object] to sails_c_create_biologicalreport
verbose: Introduced model sails_c_biologicalreport_14
in authenticated
in addCreatedBy
Total Pollens is now 0.64
Total Mold Spores is now 0.208
verbose: Published [object Object] to sails_c_create_biologicalreport
verbose: Introduced model sails_c_biologicalreport_15

http.js:673
    throw new Error('Can\'t set headers after they are sent.');
          ^
Error: Can't set headers after they are sent.
    at ServerResponse.OutgoingMessage.setHeader (http.js:673:11)
    at ServerResponse.res.setHeader (/home/jbeard4/.nvm/v0.8.21/lib/node_modules/sails/node_modules/connect/lib/patch.js:62:20)
    at ServerResponse.res.header (/home/jbeard4/workspace/testProject/node_modules/sails/node_modules/express/lib/response.js:280:8)
    at ServerResponse.res.json (/home/jbeard4/workspace/testProject/node_modules/sails/node_modules/express/lib/response.js:135:8)
    at exports.definition.actions.create (/home/jbeard4/workspace/testProject/node_modules/sails/lib/scaffolds/controller.js:133:17)
    at module.exports.done (/home/jbeard4/workspace/testProject/node_modules/sails/lib/waterline/deferredObject.js:167:12)
    at async.forEachSeries.iterate (/home/jbeard4/workspace/testProject/node_modules/sails/node_modules/async/lib/async.js:116:25)
    at promiseCallback (/home/jbeard4/workspace/testProject/node_modules/sails/lib/waterline/deferredObject.js:162:13)
    at /home/jbeard4/workspace/testProject/node_modules/sails/lib/waterline/collection.js:649:10
    at Quit.module.exports._.extend.host [as _callback] (/home/jbeard4/workspace/testProject/node_modules/sails-mysql/MySQLAdapter.js:61
6:12)