Assorted Joystick fixes

Implemented use of DirectInput sliders.  They were previously lumped in with axis and then not read or used at all.

Lots of use of joystick_type == 7 or joystick_type != 7 to detect if the joystick_type was none.  Changed this to a define.

The text to enumerate the types of joysticks was contained in a numbered LPARAM sheet.  Switched to using the name listed in the joystick struct.

Joysticks with more than 32 buttons would overflow the plat_joystick_state button array.  Added overflow checks.

Added a 4 axis 4 button joystick type that Win98 can pick up as a generic 4 axis 4 button controller.

src/win/win_joystick_xinput.cpp

@@ -216,7 +216,7 @@ void joystick_process(void)
 {
         int c, d;
 
-	if (joystick_type == 7) return;
+	if (joystick_type == JOYSTICK_TYPE_NONE) return;
 
         joystick_poll();