change PSMove mouse button bindings

[future-figs]

The current PSMove bindings activate the Select button whenever Mouse1+Mouse2 are pressed at once. This is problematic if Select brings up a menu or something (which is pretty likely), since this button combo gets pressed a lot, usually not on purpose.

For one example, see Child of Eden, where Select brings up the calibration screen and Trigger/Move shoot different projectiles. It's unplayable with the current bindings, since Mouse1 and Mouse2 are constantly getting pressed at the same time during gameplay.

In this PR, the middle mouse button now serves as a modifier (a "shift key"). It doesn't send any button-press on its own -- it just changes what the rest of the buttons do. This is much less prone to accidental combos.

Mapping with Mouse3 not pressed:

• Mouse1 = Trigger
• Mouse2 = Move
• Mouse4 = Circle
• Mouse5 = Cross

Mapping with Mouse3 pressed:

• Mouse1 = Select
• Mouse2 = Start
• Mouse4 = Triangle
• Mouse5 = Square

I also added a "Mouse9" key for consistency -- it's required now that Mouse3 doesn't bind to any buttons.

I can't be sure if this layout is ideal for every PSMove game, but until proper PSMove keybinding is implemented, this seems like a better default setup.

[Megamouse]

There are no 9 buttons in cell.
Please either remove it or add a comment to the enum value.

[future-figs]

Oh, my bad. I'll change back to just 8 mouse buttons and adjust the bindings.

[future-figs]

Updated with all Mouse9 stuff reverted/removed.

The original setup didn't require any button combos from an 8-button mouse user (although the combos were still in effect). Since Mouse3 doesn't map to anything on its own now, this means that exactly one combo is unavoidable even with an 8-button mouse.

On the other hand, I have never seen such a mouse and I think it's much better to optimize for the common 5-button mouse.

[scju]

In Time Crisis: Razing Storm I can't confirm the calibration even if I press Mouse3 and Mouse4 (=triangle).

[scju]

I don't know why, but it always seems to be on pattern (1), even when I've pressed Mouse3.

--
(1) Mapping with Mouse3 not pressed:

Mouse1 = Trigger
Mouse2 = Move
Mouse4 = Circle
Mouse5 = Cross

(2) Mapping with Mouse3 pressed:

Mouse1 = Select
Mouse2 = Start
Mouse4 = Triangle
Mouse5 = Square