Fixed issue #1074 : delay welcome message until it's the right size

Now am holding the welcome message and posting it only when everything else has been loaded.
Taking care of the comment you had posted in #1096.

"I would prefer to handle this as an application problem rather than a UI problem; that is to say, delay the message rather than its container. Nonetheless this is a welcome first attempt and I'll try it out."

Closing PR #1096 and raising new one as its on very old code. Committing there would have shown lots of differences so avoiding merge issues.
@gordonwoodhull Please review and let me know if this is fine.