Fixes:
- Clean close connections correctly when stopping the server
- Fix off-by-one error in number formatting (e.g. content-length)
- Close WebSockets properly when shutting down the server.
- Handle percent encoding of URL and request parameters.
- WebSocket example: Hostname instead of IP

New "Features" and other changes:
- Add HTTP Status Code 431 - Header too long
- Added doxgen documentation
- Some Typos
- Allow modification of HTTPSServerConstants using CFLAGS
- Configurable logging
- Use spaces everywhere

Breaking Changes:
- HTTPConnection::clientError/serverError -> raiseError(code, reason)