This commit fixes the bug that DATA is not consumed if
nghttp2_http_on_data_chunk is failed.  It also simplify the handling
of missing stream in NGHTTP2_IB_READ_DATA state.

This commit documents NGHTTP2_ERR_DATA_EXIST also occurs if HEADERS
has been already attached to stream too.  This commit also fixes
possible assertion error, and now nghttp2_submit_headers() and
nghttp2_submit_response() may return NGHTTP2_ERR_DATA_EXIST.  But we
recommend to use nghttp2_submit_request() and
nghttp2_submit_response(), and using them will avoid this error.

* fix build broken by recent changes
* place all build artifacts to OBJDIR
* explicitly add manifest (VC9/10)
* modernize python bindings creation
* some minor refactoring

Patch from Klaus Ziegler

comment of pushed moved from request to entry array
added stream_id as string to connection element as string

The syntax for this variable is the same as nginx: if SSL/TLS session
was reused, "r" is produced.  Otherwise ".".

This commit add following 3 log variables to SSL/TLS connection:
$ssl_cipher, $ssl_protocol, $ssl_session_id.  If no information is
available for them, '-' is produced for each.

It seems that HAR 1.2 does not have a proper representaion for pushed objects. I could´t just add a custom parameter so I think a comment at response will not hurt anybody.

Use std::map::insert instead of std::map::emplace, since gcc-4.7 does
not support the latter.

Fix typo

This is regression introduced in
46b70c1d.