Parse the reason phrase to make it available to NodeJs


Hey guys,

there is an open pull request that is five months old to allow the status message to be parsed. You can see this here: joyent/http-parser/pull/149.

I believe this related to this feature request: Feature Request on node.js: joyent/node#4614

These changes build on VanCoding's changes by fixing the tests, refactoring the style slightly (to make it more consistent with the rest of the file) and adding an extra test for another case that was previously untested. 

I understand there has been some discussion in the community as to whether this feature is actually useful. I'm happy to explain why I think it is useful if necessary.