Comments on HTTP API before publishing FPWD

Hi all,

At the f2f we agreed to make a call for consensus to publish a FPWD of the
HTTP API. Before we do that I ask that any changes or comments be submitted
that will avoid us having to deal with these after the CfC.

Please review the spec and submit your comments or PRs by Tuesday next week.

I have done a review of the latest draft and have the following comments:

I have submitted a PR with some concrete changes that:
- sync the diagram with the accompanying text:
- change the flows to be more aligned with what the group has agreed upon
for pull-based payment methods (like basic card)
- add issue markers

https://github.com/w3c/webpayments-http-api/pull/2

I tried to separate these into commits that could be cherry-picked if
necessary.

Some general comments:

*Flow diagram*
This created a lot of confusion in the f2f.
- We should drop the term token/tokenized. I'm not sure it adds any value
- Step 11 in the current flow doesn't seem feasible in a client server
setup. This looks like server push.


*Terminology*
If we are going to pull the terminology in we need to fix it up asap. If
it's going to be used in public working drafts it needs a clean up.


*Push Payments*
We need to demonstrate both a push and a pull based payment. This is still
very pull based.


*NOTE:*
As a group we committed to getting the work on payment apps done as
priority and accepted this work as long as it didn't have a negative effect
on other higher priority work.

If there is a significant amount of work to do on this document then I
would not encourage us to push it to FPWD yet and to hold off until the
group can give it due attention.


Adrian