[eclipselink-dev] check in for bug 368365

[Christopher Delahunt <christopher.delahunt@xxxxxxxxxx>]

bug 368365 -add DDL support to alter existing tables to add missing fields
https://bugs.eclipse.org/bugs/show_bug.cgi?id=368365

Small change to issue create table DDL statements first, and only query 
for existing table metadata if create table fails.  This works in more 
cases than querying first and creating the table if no metadata exists 
when dealing with multiple schema's - potentially common until 367887 is 
resolved.

checked into 2.4 at revision 10995
Reviewed by David Minsky