be incorrect on the first pass and only be correct when remade.
The reason was that disp-exp.cnf was created incorrectly on first pass.
disp-exp.cnf required dop-exp.cnf to build correctly, so add a mechanism
to add dependencies for export files.
Note: Only the cmake change has been tested, the autofoo stuff requires
testing.
svn path=/trunk/; revision=52120
