fix memcached-tool to print about all slabs

previously hardcoded to 40. now will iterate up through all of them.

scripts/memcached-tool

@@ -136,10 +136,12 @@ my %items;  # class -> { number, age, chunk_size, chunks_per_page,
 #            free_chunks, free_chunks_end }
 
 print $sock "stats items\r\n";
+my $max = 0;
 while (<$sock>) {
     last if /^END/;
     if (/^STAT items:(\d+):(\w+) (\d+)/) {
         $items{$1}{$2} = $3;
+        $max = $1;
     }
 }
 
@@ -152,7 +154,7 @@ while (<$sock>) {
 }
 
 print "  #  Item_Size  Max_age   Pages   Count   Full?  Evicted Evict_Time OOM\n";
-foreach my $n (1..40) {
+foreach my $n (1..$max) {
     my $it = $items{$n};
     next if (0 == $it->{total_pages});
     my $size = $it->{chunk_size} < 1024 ?