metadata fixes and 'sqlmp' code cleanup -- NATable struct for metadata was being created multiple times whenever information for a new table was read from metadata. That has been fixed. -- an 'initialize trafodion, drop' followed by 'initialize traf' from the same session was failing due to priv info not getting reset. This would show up if 'initialize authorization' was done earlier. That has been fixed. -- code cleanup mostly related to sqlmp legacy code and reference.