Github vs hcards - invalid email addresses parsed

[CloCkWeRX]

Github for some particularly annoying reason likes to render email addresses with javascript content in the hcards. It would be particularly useful if there was a quick email validation which only accepted valid email addresses in hcards - or a utility method at the very least; which allowed you to test validity.

Reproduce steps:

1. Grab 3e7265a and friends
2. Visit https://github.com/CloCkWeRX
3. Add to google contacts

Expected:
Success

Actual:
Failure; as invalid content is being passed around.