Merge from HTTP/2 - Connection header 25 bytes=>24 bytes.

Dropped the 'R' from BAR in the connection header magic byte sequence.
Update HTML/TXT too
Some copy/pastes from HTTP/2.

Picks up some newer HTTP/2 updates. No substantial changes, just editorial.
Merge pull request #19 from willchan/UpdateConnectionHeader

Update connection header
Fixup HTTP/2.0=>SPDY
Merge pull request #20 from willchan/Editorial

Some copy/pastes from HTTP/2.