add syndication reload button to the settings screen

makes the login experience a bit friendlier to non-developer users

likes and reposts the tweet on twitter first, then sends a syndication URL in the micropub endpoint

let's give this a shot

closes #71

* new route `/edit?url=` intended to be used as an edit button target, which detects the type of post and redirects to the appropriate editing interface
* implemented the edit interface for favorites

closes #69

* adds setting to choose the property to use for the syndication targets
* all existing users default to the old value `syndicate-to`
* new users default to `mp-syndicate-to`

closes #66

* shows reply context of the URL you're replying to
* autocomplete nicknames from the post when replying
* moved debug info to the settings screen to clean up the UI

* looks for a media endpoint in the micropub config
* if media endpoint is available, both the note interface and the editor will upload files to it instead of posting the photo directly
* the note interface autosaves in-progress notes in localstorage

Quill corrects the photo rotation based on exif data since iOS tends to take landscape photos and set the rotation bit when holding it in portrait mode.