Login Email

Login via email broken off into it's own module from logintoboggan's login via email and #111317: Allow users to login using either their username OR their e-mail address .

1. Allow Logging in with username, email, or both.
2. Make sure all places in core that reference logging in with email are changed to reflect the current settings.
3. Account for #1359718: Allow password reset on account w username matching another email. Prevent registrations which match another account issue.

See issue #111317: Allow users to login using either their username OR their e-mail address and #660828: split email login feature out into its own module

This is a minimalist module to address one feature: to allow users to login with either their username or email address. Once the module is enabled you can configure it at:
/admin/config/people/accounts