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

Fix h-entry with h-card before it

The previous check removed a h-card, but this one still takes the first of the original array. Which means, in the case of `h-card+h-entry`, the h-card get’s removed, but then the if triggers and the `h-card` is selected.

replaces #78

closes #79

* a single h-entry and h-card, where the h-entry has no URL, will result in a permalink page with that h-entry
* multiple h-entrys followed by an h-card is a feed

closes #77

including from rel=alternate

* mf2+html
* mf2+json
* feed+json
* xml
* instagram/facebook/github/xkcd

returns a new property `post-type` next to `type`

closes #25

closes #73

parse from both link tags and the u-redirect-uri property