Post response move pagination -> meta

closes #2604
- moved ‚pagination‘ to ‚meta‘ property
- added response test for pagination property
- changed ‚next‘ and ‚prev‘ to be set to null and exist on every
response
- removed unnecessary call to API for RSS author
Merge pull request #2617 from sebgie/issue#2604

Post response move pagination -> meta
Do not show edit screen if any string other than '/edit' to post URL

closes #2619
- added 'edit' string check for anything appended to the post URL
- this fixes redirecting to the post's edit screen if a random string is entered after the post URL
Added tests for /edit/ and /nonexistentpost/edit/

Closes #2619
- moved edit tests into its own test suite named EDIT
- added tests for <blogurl>/edit/ and for posts that dont exist
Added 404 redirect if params.edit !== edit and is defined.

Ref #2619
- Added redirect to 404 to show decisive action when appending anything other than 'edit/' on post URL
- Modified EDIT testsuite to test for 404 when above happens