Login redirects to wp-login if using email address

Hi, I created a dummy account to test with. When you use the Login menu from the header menu, if you enter your username and password everything works as intended, however, if you were to enter the e-mail address that was used to register instead of the username, it redirects you to the WP-login page which I do not want to have happen. I understand that it says “username” in the dropdown for login, however, I am used to using both email address and username interchangeably when logging in to various accounts and I don’t imagine that I’ll be the only one to do the same.

I’d like to know:

– Is there a way to allow logging in using e-mail address as well as username? If so, how can I do this?
– If there is no way to allow email and username for logging in, rather than go to my wp-login page, can I have it go to an error message page that says something like “Please enter the username you registered with and not the e-mail address” or whatever I want it to say?

The important thing here is that I don’t want it going to my wp-login at all.

Thank you for your time and help!

Link to site: http://goo.gl/lpEbkf