Adding note on reuse of http:/https: default ports.
Fix error handlings on HEADERS and PRIORITY

Error when stream identifier field is 0x0 is not stream error but
connection error
Merge pull request #113 from shigeki/shigeki_20130611

Fix error handling references on HEADERS and PRIORITY
Corrected description of disabling flow control

Flow control can be disabled by WINDOW_UPDATE with END_FLOW_CONTROL.
Corrected description of CANCEL

3.4.1 Stream Creation says that either endpoint can send CNCEL.
Merge pull request #115 from shigeki/shigeki_20130612

Expanded description of disabling flow control
Merge pull request #116 from shigeki/shigeki_20130612_2

CANCEL can come from either endpoint
Painting the bike shed a different colour.  Closes #101.
8-byte ping frame as discussed in the interim
Merge pull request #121 from jasnell/ping-limit2

8-byte ping frame as discussed in the interim
Making GOAWAY SHOULD.
Merge branch 'master' of github.com:http2/http2-spec
Exercising editorial discretion regarding magic.