This is stage one of a number of changes to improve this dialog.

This fixes a missing icon bug for writer. Writer tried to load
cmd/sc_editheaderfooter.png but only cmd/sc_editheaderandfooter.png
existed. Calc is using cmd/sc_editheaderandfooter.png so I assumed
this is the right way.

This reverts commit d0a69c9a because
make dev-install's smoketest is failing on --enable-debug and
reportedly no --enable-debug

This fixes the build of 'basic' on Windows.

These semantics are fairly horrific, but existing code expects them, so
callers need to be changed if this is changed.