0.5.0

• Support server variables, headers, and query string
  processing to allow using the embedded PHP to process http
  requests from node's http server.
• Support passing "command-line arguments" to allow the embedded PHP
  to execute scripts using PHP's CLI interface.
• Add a simple php-embed CLI script for easy testing.
• Allow PHP to invoke asynchronous JavaScript functions synchronously
  by passing a Js\Wait object where the callback would go. This
  blocks the PHP event loop (naturally) but not the JavaScript one.
  This is used internally to implement PHP requests to flush the
  output stream.
• Wrap PHP objects (but not yet arrays) for use within Node.
  Property access is implemented; method invocation is not yet
  implemented.
• Rework message passing to allow two-way communication between JS
  and PHP. Both JS and PHP have event loops now, and both can do
  asynchronous method calls (but at the moment most calls are
  synchronous).
• Aggressively lint the C++ and JS code bases.