Bug 2900: fix GetPendingIssues.

Bug 2900: fix GetPendingIssues.

GetPendingIssues did several bad things:
~ select * on a 4 table join,
~ including multiple namespace collisions,
~ including large fields marc and marcxml from biblioitems,
~ return ($count, \@array_being_counted).

Not everything is fixed here (see FIXMEs), but the situation is
improved considerably, with bug 2900 resolved.  The "timestamp"
namespace collision in query should be resolved by separate patch.

Signed-off-by: Galen Charlton <galen.charlton@liblime.com>
Signed-off-by: Henri-Damien LAURENT <henridamien.laurent@biblibre.com>