WL#2981: Get timestamp from cluster for Datetime fields, like NOW() in MySQL

Currently NTP must be used on all machines having cluster nodes. As this works 
fine, it would be nicer for the clients to ask for the time from the cluster and 
use that when inserting or updating records which need current timestamp.

Maybe the Arbitrator could provide this information, or the Master data node 
through an event.. These machines should be sync'ed with NTP anyway.

This would mean more traffic, aka 'slowing' things down, but at least all SQL 
nodes will have the same time. Also no problem with machines that would have a 
different timezone setup or running behind because NTP failed.

The NOW() function used in MySQL is an example, which is very useful in 
development since server time is used. Applications can't rely on having the 
correct time locally, the Database server is correct (usually).