Send a special request header on an update check so that the recipient server can forward to a .meta.js file.
Set the Accept header to let the server know we want a user script metadata block. Closes #1824.
Merge pull request #1825 from sizzlemctwizzle/issue-1824

Set headers on HTTP requests that GM originates.

Fixes #1824
Add myself to contributors.
Keep the AOM list item enabled status up to date.

Fixes #1811