Limit the Admin Queues list to 50 rows per page by default

Otherwise instances with a large number of queues take forever to load
and display (such as rt.cpan.org).

    (cherry picked from RT commit 944109e78909187e4427557380f16f34a93c9727)
Fix queue summary ("Quick Search") with non-lowercase statuses

798505e forced statuses to be stored in lower-case in the database.
However, the loop in QueueSummaryBy... stored the counts from the GROUP
BY (which are lower-case) in a hash, and looked them up by canonical
case -- resulting in "-"s displayed for all non-lowercase statuses.

Add the necessary lc() calls in the hash lookups to find the grouped
results.

    (cherry picked from RT commit 5a5579867ae459ce3c55571450a501220ba9b3a8)