Fixing typo
Merge pull request #161 from MikeBishop/layering

Fixing typo in HEADERS example
Merge pull request #160 from hruellan/layering

Layering editorial corrections
Add opaque data to GOAWAY.
Replaced an incorrect flag name with a correct one
Restoring :scheme to examples.
Removing associated reset for promised streams.
Merge branch 'patch-1' of git://github.com/gongloo/http2-spec into gongloo-patch-1
Adding note about minimal processing requirements for frames after sending GOAWAY, like for RST_STREAM.
Clarifying the debug data description for GOAWAY.
Making it easier to build non-standard-named output.
Correcting makefile error.