git-svn-id: https://samskivert.googlecode.com/svn/trunk@2312 6335cc39-0255-0410-8fd6-9bcaacd3b74c
unlikely that one would do the latter), automatically remove obsolete columns (might be dangerous, I could be pursuaded to reconsider). git-svn-id: https://samskivert.googlecode.com/svn/trunk@2013 6335cc39-0255-0410-8fd6-9bcaacd3b74c
git-svn-id: https://samskivert.googlecode.com/svn/trunk@2007 6335cc39-0255-0410-8fd6-9bcaacd3b74c
git-svn-id: https://samskivert.googlecode.com/svn/trunk@1774 6335cc39-0255-0410-8fd6-9bcaacd3b74c