Access-Control-Allow-Origin:* header added to API responses to allow
angular to access API.

Note: This allows all domains to access this API through browser javascript

See <https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS> for a
description of CORS

Combines APIResponseItem and APIResponseList into one struct. Hopefully
this allows for the combination of some response code (a function
that sends a APIResponse that can be used by each http method)

Also adds error for POST to individual resource

Transactions allow us to rollback inserts ensuring that the database is
in sync with our application.

When updating ingredients if some # are remove we need to remove the
same number from the database and update the rest, without an id column
we don't know which ones to delete.

Changed database schema so ingredients & steps does not have an id, and
therefore can't return it so instead we just exec the insert statement
without returning anything.

We do have to check that there were affected rows in order to accurately
update the recipe object.