tighter "living person" edit

[JanetBjorndahl]

Treat a future date as an error (show an error message but don't require it to be fixed before saving the page - same as most date errors for now). If born in last 110 years, require one of the following to save the page:

• valid death or burial date, excluding a date using "aft" or "est" modifier
• death date of "(in infancy)" or "(young)"
• famous living person exception template