CrossOriginResourceSharing

Added the \CivicInfoBC\CrossOriginResourceSharing class, which allows for simple server side implementation of cross-origin resource sharing.

The class takes an array of allowed origin domains in its constructor, and when its Send method is invoked checks the "origin" header for a match.  If there is a match, it sends the "access-control-allow-origin" header, set to the appropriate value, thereby allowing the request.
JSON::Get

Added the Get static method to the \CivicInfoBC\JSON class.  This method fetches the body of the current request and decodes it as JSON.
Renderable Interface

Added the Renderable interface, which is an interface classes may implement if they can be output as HTML by calling their Render method.
Template implements Renderable
HTML::Parse

Added the Parse static method to the \CivicInfoBC\HTML class.

This method uses libxml to parse HTML into a \DOMDocument object.  In so doing it avoids the pitfalls of using \DOMDocument::loadHTML directly:

-	It ignores warnings (unless $strict=true), rather than spitting them to stdout (if display of errors/warnings is enabled, which it should be in a development environment, which makes consuming HTML with libxml incredibly noisy)
-	It translates errors (and warnings, with $strict=true) to exceptions