Made ":"-header fields appear first in both requests and responses

This should address issue #23
Reworded the requirement on header field names to use normative language
Removed :version as per discussion in Orlando

Not used for anything.
Initial attempt to add PUSH_PROMISE and associated changes
remove authentication related text (#49)
Fixing line wrapping.  In emacs: C-u 100 C-x f C-x ( C-M-s .\{100,\}<enter> M-q C-x ) C-u 1000 C-x e
Some updates on frame description.
Merge branch 'frames' of https://github.com/hruellan/http2-spec into frames

Conflicts:
	draft-ietf-httpbis-http2.xml