Adds 201 response for PUT.

According to RFC2616: "If a new resource is created, the origin server MUST inform the user agent via the 201 (Created) response."
Updates Webfinger properties and reference.

Instead of the string 'auth-endpoint', use the URI of the auth method as property name, because:
1) According to the Webfinger specification: 'The "properties" object [...] names are absolute URIs'.
2) This allows implementations to provide multiple, complementary auth methods.
Merge pull request #1 from steventebrinke/master

Compliance with referred specifications