Some POST samples.
Merge pull request #886 from square/jwilson_0531_post_recipes

Some POST samples.
Give each recipe its own file.
Merge pull request #888 from square/jwilson_0601_file_per_example

Give each recipe its own file.
Cancel recipe.
Merge pull request #889 from square/jwilson_0601_cancel_example

Cancel recipe.
Write continuation frames when hpacked data is larger than 16383 bytes.

Change max frame size to a constant.