#3191 A collection of bad-data warnings: .pm files

[Jamie McCarthy]

1. Slash.pm _can_mod()

This one's odd, since I don't see how $comment->{uid},
$comment->{lastmod}, or $user->{uid} could ever be non-
numeric. But a couple hundred times a day we're seeing:

Argument "" isn't numeric in numeric ne (!=) at /usr/local/lib/
perl5/site_perl/5.6.1/i686-linux/Slash.pm line 438.

2. Display.pm portalbox()

This one's easy, we need a different default than 'index'

Argument "index" isn't numeric in numeric eq (==) at /usr/local/
lib/perl5/site_perl/5.6.1/i686-linux/Slash/Utility/Display.pm line
907.

3. Slash.pm selectComments()

Weird one.

if $C->{points} >= (defined $user->{threshold} ? $user-
>{threshold} : $min)

Argument "..." isn't numeric in numeric ge (>=) at /usr/local/lib/
perl5/site_perl/5.6.1/i686-linux/Slash.pm line 170.