* Made it possible to add digital controls to axis settings as enables.
* Mix multiple analog controls assigned to an axis setting.
* Added a "reverse" modifier for analog controls (useful with mixing).
* Fixed an issue assigning mouse axes using multiple mouse-like devices
with -nomultimouse.
-frontend: More cleanup:
* Got rid of some abuse of "special main menus".
* Added a helper class for auto-pause menus that don't spawn submenus.
* Got rid of the fake menu that schedules an exit on the first frame.
* Turned the confirm quit prompt into a menu, eliminated one more
special-cased event loop.
* Fixed the confirm quit prompt resuming if you return to emulation if
you weren't paused to begin with.
-bus/centronics: Fixed conflicting DIP locations, reversed order and
inverted polarity for Epson printers.
* Also added the LX-810 (without L suffix) DIP switches for reference -
we don't have a device for this printer yet.