now supports pkce

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

fixes relative URL resolution (closes #78) by relying on new IndieAuth\Client package.

closes #71

update to "create" scope by default, but allow the user to choose "post" as a fallback. also updates indieauth/client to 0.2 for json support.

closes #67

* 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

paths are allowed in Quill URLs now

With this it is possible to post a photo note with a description, nothing
more. It doesn't move the file in the file system, just posts it from
the temp location to the users server. It also does validate for file size,
content type and max upload size and shows the errors to the user.

If everything goes according to plan the response from the users server
is shown, together with a link with the posted photos URL.

* Supports a bookmarklet to create "like" posts.
* Beginning a "settings" page to connect silo profiles for POSSEing likes to twitter, facebook and instagram