* DBModeler/GNUmakefile: Add new file.
* DBModeler/DefaultColumnProvider.m: Reorder table columns.
Use new file, for allows null column. Remove out of date comments.
git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/gdl2/trunk@23533 72102866-910b-0410-8b05-ffd578937521