is_integral_domain crappy output

[Robert Miller]

In sage/rings/quotient_ring.py, we have the following (line 220 in
2.8.14):
try:
return self.defining_ideal().is_prime()
except NotImplementedError:
return False

Why the heck don't we just propagate the NotImplementedError!?!

[William Stein]

Good point. Change it and submit a patch. And make sure to doctest
everything, and include doctests illustrating your patch.

-- William