Initial pass at rewriting the PHP port for modern PHP.
More small improvements to the Composer-friendly version of the PHP port.
Removed all non-PHP languages, and moved the PHP code to the top level of the project.
More cleanup.
Merge branch 'feature/php53-port' into develop

* feature/php53-port:
  More cleanup.
  Removed all non-PHP languages, and moved the PHP code to the top level of the project.
  More small improvements to the Composer-friendly version of the PHP port.
  Initial pass at rewriting the PHP port for modern PHP.