frame header changes
disable deprecation warning for RSpec #should
apparently Server#dup isnt deep enough
unify END_HEADERS flag
Merge pull request #12 from phluid61/common-frame-header

add (extra length) byte to common frame header
Merge branch 'header-continuation' of github.com:phluid61/http-2 into phluid61-header-continuation

Conflicts:
	spec/framer_spec.rb
Merge branch 'phluid61-header-continuation'
Merge branch 'master' of https://github.com/igrigorik/http-2 into unknown-types
update common frame header lengths