DGen

When some sdl option is set in the .dgenrc, but dgen doesn't receive any
sdl command line option, it ignores the ones in the dgenrc. This is because
the initialization is done in pd_option, but it doesn't get called if there
isn't any command line option for him. It can be fixed with (lots of)
changes to the sdl.cpp file, but the easier (and hack-ish) way was to force
a call to pd_option even if not needed.