Remove FLAG_END_FLOW_CONTROL as it is no longer in http/2.  Backfill test and implementation window update on http/2.
Add GOAWAY support to http/2 and backfill tests.
Merge pull request #476 from adriancole/http2-goaway

Add HTTP/2 GOAWAY frame
convert http/2 params to natural primitive types.
Merge pull request #477 from adriancole/ids-and-fields

frame metadata field cleanup
Simplify settings and hide SPDY Variant construction.
Merge pull request #479 from adriancole/hide-settings

Simplify settings and hide SPDY Variant construction
Fixed bad length bugs in http/2 reader, ignore unknown frames, and cleaned up frame handling.
Merge pull request #478 from adriancole/harden-reads

cleanup frame handling in http/2
Backfill spdy and http/2 related tests wrt zero-length messages.
Merge pull request #480 from adriancole/backfill-tests

Backfill spdy and http/2 related tests wrt zero-length messages.
Create concurrency doc.
Improve some Markdown
Style fixes
Merge pull request #9 from square/master

sync origin