Use parse_headers for media endpoint uploads

micropub_media_post_for_user makes a case-sensitive search for the
Location header, which fails if the location header is all lowercase.

This change uses the `headers` fields, introduced in
2b98a4548e82f1133bf62918b0106ab99a21fa29a, to find the Location header,
regardless of case.

Fix reload targets

closes #112

🙈

the API dropped their free tier

remove trailing comma in sqlite schema

should help clear out the draft when a post is created.

for #109

now supports pkce

Simple Addition of Profile Data to Quill

still shows debug messages when missing endpoints to help people get started

add syndication reload button to the settings screen

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