danielbachhuber/WP-By-Email — pull request #10 by jeremyfelt (2014-03-10 21:59:10+00:00)
Title: [PR] Key WPBE user meta for compatibility with multisite

If multisite, add the site ID to the user meta key. This enables
a user to have different email notification settings for each
site.

Renames `$options_key` to be the more descriptive `$user_meta_key`

Closes #6