consolidate protocol constants
Merge pull request #438 from adriancole/consolidate-protocol

consolidate protocol constants
Introduce BitArray, a simple BitSet clone that supports shifting.
Merge pull request #453 from square/jw/bit-array

Introduce BitArray, a simple BitSet clone that supports shifting.
Support more than 64 referenced headers in HPACK.
Merge pull request #452 from adriancole/hpack-gt-64

Support more than 64 referenced headers in HPACK