* po/client-http2:
First implementation of the client GET/POST methods with HTTP/2.
Minor code refactoring to prepare HTTP/2 client support.
Add Append_Body version for a Response message.
Add Append version for a Response message in Data frame.
Add Create routine for a request message.
Add support for retreiving the GoAway error code.
Add support for Stream.Data_Fow to report current data direction.
Minor code clean-up.
The right context of the HTTP/2 request and responce is not in the TCP
connection but in the HTTP/2 stream.
To check this put 2 few megabites length files into web_elements directory,
run demos/wps executable, and then call
h2load https://127.0.0.1:4433/{big-file-1,big-file-2} -v -w 14 -m 2 -n 8
TN: S507-051
When size of gzipped stream is few bytes more than multiple of
Read_Buffer_Size stream creation parameter, the end of stream can be
detected only after last empty read. To fix that we should try to read
and inflate ahead.
TN: U727-039
Do not load all message body into memory.
Load data depend on frame window available.
Remove caching from AWS.Resources.Streams.Disk because it has error
detected by use in HTTP/2 and does not really need because streams
reading by big chunks usually.
Part of S507-051.