That allows direct comparison with hogweed's RSA results.

Fixes problem with windows dll linking.

Use the EXEEXT_FOR_BUILD when calling the generated desdata
program, otherwise the build fails when cross compiling because
keymap.h and rotors.h are not found.
Signed-off-by: Claudio Bley <cbley@av-test.de>

Signed-off-by: Claudio Bley <cbley@av-test.de>

Problem reported by Peter Eriksson.