Changes

CheckpointGCthreadCount conflicts with gcThread Warning

CheckpointGCthreadCount is expected to be no larger than
the number of gc threads.

We have two cases here:
1. If the user doesn't set the checkpointGCthreadCount,
the amount is adjusted to match the number of gc threads

2. If the user sets the checkpointGCthreadCount, a warning
is generated and the checkpointGCthreadCount is ignored

Signed off by: Frank.Kang@ibm.com
 (commit: c9f23da)