Bulk

- Modified the meaning of 'rc.bulk'.  The old meaning was: the largest number
  of tasks that could be modified without confirmation.  New meaning is: the
  number of tasks that trigger bulk confirmation.  Default was 2 (meaning that
  2 tasks affected were not in need of confirmation), is now 3 (meaning 3 tasks
  now trigger confirmation.
  Despite the dog's dinner I made of the preceding statement, the configuration
  variable is now easier to understand.

test/bug.bulk.t

@@ -35,7 +35,7 @@ if (open my $fh, '>', 'bulk.rc')
 {
   print $fh "data.location=.\n",
             "confirmation=yes\n",
-            "bulk=2\n";
+            "bulk=3\n";
   close $fh;
   ok (-r 'bulk.rc', 'Created bulk.rc');
 }