Header Image & Link Verification

Hey Chase!  I hope this message finds you well. 

age-verify is a great plugin that came in handy for a project that I was working on.  

I extended age-verify just a little bit to allow for a custom "age gate header image", and also to allow for users to submit the age verification form by clicking on a link.   

The header image upload makes use of the file_frame media uploader tools.  It's pretty sweet! 

Have a look at my changes and LMK what you think.

All the best

-Matt