Add nghttp2_session_handle_invalid_connction to simply code
nghttp2_session_handle_parse_error: Call nghttp2_session_fail_session
nghttp2_session_handle_invalid_stream: Remove stream_id parameter
Handle invalid stream ID (== 0 or != 0) cases
Add nghttp client backed by libevent
Add nghttpd and 24 bytes client connection header support
Remove spdyd and spdycat
Code cleanup
Rename nghttp2_ssl as app_helper
Update README.rst
Support PRIORITY frame send and receive
src: Print PRIORITY frame in print_frame()
Call nghttp2_session_handle_invalid_connection if stream_id == 0 or != 0 case
Send PRIORITY with current stream priority
Remove push related members from nghttp2_stream