Priority edits.  Closes #464.
Closes #469
Altering stream priority description, introduces 'parent' terminology.  For #465.
Attempting to making dcsommer happier.
update http2 reference
define tunnel/gateway/proxy as well (#427)
Wording tweak
Merge branch 'master' of https://github.com/http2/http2-spec
add missing 'is'
Removing reserved byte from ALTSVC
Merge pull request #471 from phluid61/copy-edit-260414

add missing 'is'
Removing implementation note.
Merge branch 'master' of https://github.com/http2/http2-spec
update to latest version of rfc2629.xslt
Updating address
remove obsolete comment about where security considerations go.
Proposed text for #458
Fix typo: "vulnerabilites"
Merge pull request #476 from rutsky/patch-1

Fix typo: "vulnerabilites"
Use "name = value" consistently for headers

There has been some inconsistency in the format used for headers, with some
using "name: value" and others using "name = value". As these are only
approximations, either is fine, but internal consistency is desirable.

With the colon-prefixed names now extant, ":name = value" is subjectively
clearer than ":name: value"; for this reason, I have normalised headers to
"name = value" rather than "name: value".