Added scripts to test server

- Scripts in /tests sends arbritrary openid messages to server
Added 405 return message for http handling
openid::provider refactoring

- Changed format of log messages
- Fixed log report on successful closing of http::connection
- Changed interface of server initialization
- Removed openid::provider singleton pattern
- http::reply charset changed to utf-8
- http::request added return uri method
- Changed format of exception catch to take const refs
- Simplified server initialization
- Code refactoring on openid::provider
- Creation of request hierarchy
- Implementation of provider discovery
- Fix on provider nonce generation
- Fix on provider nonce storage
- Fix on provider indirect error response