Adding `restify.realizeUrl` for replacing URL params with values from a hash.

Example: `restify.realizeUrl('/foo/:bar/:baz', {bar: "BAR", baz: "BAZ"}) === '/foo/BAR/BAZ'`

In the process factored out `sanitizePath` method from request.js into a new utils.js module.
Merge pull request #134 from domenic/realize

Adding `Route.prototype.realize`.
Fix defaultResponseHeaders setter
Merge pull request #137 from hmarr/fix-default-header-setter

Fix defaultResponseHeaders setter
workaround joyent/node#3257
fix json_body_parser comment
Merge pull request #142 from davepacheco/master

workaround joyent/node#3257
test for GH-141
lint cleanup
version bump
prep for future dev
Add support for authority certificates
Merge pull request #144 from pbouzakis/authorityCertificate

Add support for authority certificates
Add http error 415 Unsupported Media Type
Merge pull request #145 from sstur/master

Add support for HTTP 415 Unsupported Media Type
add request body length validation to form_body_parser; add test
only parse request body for POST and PUT
add req body length validation to json_body_parser; add test
Merge: Add maxBodySize option for buffering request body; Add tests
Merge pull request #151 from sstur/master

Only parse request body for POST and PUT