Remote API documentation and examples

- API-docs/README.md: the documentation of the remote API, with one page per function
  (generated from the examples with "php API-docs/build.php").
- examples/<function>.php: a SOAP example for every function, the URL and login are set
  in examples/soap_config.php.
- examples/json/<function>.php: a JSON example for every function, the URL and login are
  set in examples/json/json_config.php.
