Exclude upper case letters from generated passwords.
Exclude upper case letters from generated passwords.

12 character passwords from the set a-z0-9 have more bits of
entropy (62) than 10 character passwords from the set
a-zA-Z0-9 (60), and are probably perceived as nicer by the
users too (less ambiguity, easier to type on smartphones and
the like).

SUNET/eduid-signup,SUNET/eduid-signup,SUNET/eduid-signup