Retain accepted content-type with no-content

[davidcheung]

rest.test.js

• Add test case to make sure default stays as application/json
• Add test case to make sure it retains specified content-type

  http-context.js

• seperate logic of figuring out what to send and sending it

Connected to strongloop/strong-remoting/issues/258

[davidcheung]

@bajtos I have refactored the implementation, can you take a look to provide some feedback to see if it make sense?

[bajtos]

@davidcheung cool, the new implementation looks great! I left few comments on what to improve, this patch is almost good to be landed.

Please ping @ritch to see if he has time to give this the final review and land it while I am offline. If he hasn't, then I can land it on Monday.

[davidcheung]

@bajtos I have updated the code as per suggestions, looks much nicer now.

@bajtos or @ritch, please review

[bajtos]

LGTM. Landed, thank you!