Use EVBUFFER_EOL_CRLF for evbuffer_readln

This is the pull request for #6

Due to the use of EVBUFFER_EOL_ANY in evbuffer_readln the end of the rtsp header is not recognized (EVBUFFER_EOL_ANY does not return empty lines).  Changing it to EVBUFFER_EOL_CRLF makes sure that the end of the rtsp header is recognized.