Open the main window with the correct width and height, depending on
both the selected device and the paper dimensions.

Add a command-line option to specify the paper dimensions (similar to
other groff devices).

Better error handling.

Resource and command-line option to specify font path.

Resource to specify name of environment variable from which to get the
font path.

Have character substitutions (currently done in draw.c:FakeCharacter)
specified in a resource (similar format to FontMap).

The initial width of the dialog box should expand to accommodate the
default value.

Option in Print dialog to specify that only the current page should be
printed.
