(atz, pls validate) bugfixing dates viewing on moremember

There were 2 bugs :
- one in moremember.pl that supposed the date value to be in preffered order, which is wrong, it's in iso at this time
- the output does not work as expected, as it always return iso.

Pls atz, confirm Dates.pm was bugged.

Signed-off-by: Joshua Ferraro <jmf@liblime.com>

C4/Dates.pm

@@ -98,7 +98,7 @@ sub init ($;$$) {
 }
 sub output ($;$) {
 	my $self = shift;
-	my $newformat = (@_) ? _recognize_format(shift) : $self->{'dateformat'} ;
+	my $newformat = (@_) ? _recognize_format(shift) : $prefformat;
 	return (eval {POSIX::strftime($posix_map{$newformat}, @self::dmy_array)} || undef);
 }
 sub today ($;$) {		# NOTE: sets date value to today (and returns it in the requested or current format)

members/moremember.pl

@@ -96,7 +96,7 @@ my $category_type = $borrowercategory->{'category_type'};
 $template->param( $data->{'categorycode'} => 1 ); 
 
 foreach (qw(dateenrolled dateexpiry dateofbirth)) {
-		my $tempdate = C4::Dates->new($data->{$_})->output('iso')
+		my $tempdate = C4::Dates->new($data->{$_},'iso')->output
 			or warn ("Invalid $_ = " . $data->{$_});
 		$data->{$_} = $tempdate || '';
 }