Remove unused settings.
Drop CWND too.
Merge pull request #126 from willchan/KillSettings

Remove unused settings.
update issues
typo
Merge pull request #127 from rodnaph/patch-1

typo
Dealing with retries, first try.
Updating references to retrying sample.
Oxford comma.
Fixing upgrade transition semantics.  Closes #52.
Small editorial fixes.
Adding protocol structure section stub.
Merge branch 'layering' of github.com:http2/http2-spec into layering