`strpos(string, sub)` returns `false` if `sub` is not present in `string`. In this case, we want to check if `sub` is not a *prefix* of `string`. Hence, we just need to test if the returned position is simply different from 0.

* looks through the full mf2 tree for step 7 of authorship https://github.com/indieweb/authorship/issues/2
* if no author h-card is found, falls back to returning the author URL without other data instead of missing author

closes #95

Allow iframe from YouTube and Vimeo

need to update htmlpurifier first

if the document contains a link to the target, but that link is not in the parsed result, don't return an error, but also don't return the parsed document

closes #150

for https://github.com/aaronpk/webmention.io/issues/150

closes #96

XRay now looks for images inside the HTML and does not consider those empty posts

Add support for parsing MF2 JSON

To make it possible to consume feeds of pre-rendered Microformats2 JSON
data, we need to be able to discover that it is a Microformats2 JSON
file using the known MIME types documented  in
http://microformats.org/wiki/microformats2-mime-type

move target check outside of all format classes and operating on the final parsed JSON so that it works regardless of the input content type

for https://github.com/aaronpk/Aperture/issues/56

closes #89

Now it checks that:
1. h-geo exists
2. it's a microformat
3. it's of type "h-geo"
4. that it has properties
5. that it has latitude
6. that it has longitude

If all checks are true, lat and lon get replaced with values of h-geo object.

I'm not a PHP coder, I'm just a dummy :c

This adds h-geo microformat support. It's clunky but it should work. I'm no PHP gal so I hope you have CI or something that would test it.

Test case: [this post by me](https://fireburn.ru/posts/1567956895) that should contain a checkin with h-geo embedded. Should be parsed with latitude and longitude, showing a map in applications like Monocle.

closes #92

we also need the controller files!

GAE now runs composer itself and dev dependencies are not installed

https://cloud.google.com/appengine/docs/standard/php7/specifying-dependencies

forgot a key word

let's try the default

deploy Google App Engine version to PHP 7.2

closes #86

more consistently returns HTTP 410 now

This adds a new property, "meta", which includes alt text and has room to include additional properties later.

closes #85