Add properties to a VDB to hold validation date/time and Teiid version a nd show in VDB Editor

In order for Teiid Designer to provide better validation of VDB's against different Teiid versions, it would be beneficial to add attributes defining which Teiid version a VDB was last validated against and throw in validation time-stamp while we're at it. Both values would probably be nice to see in a console environment.

<vdb version="1" name="smallvdb" validationDateTime="2002-05-30T09:00:00" validationVersion="8.4">