[Retroarch] Move gamepad input options to Retropad controls

[Slider-Whistle]

Hey, really pleased with the emulator at the moment. It runs anything I've tried putting through it pretty much perfectly. It's also great that you made a libretro port, it means that I get to use CRT SwitchRes which is just awesome.

Is it possible to assign certain keyboard controls to gamepad buttons directly? While mouseshift mode might not be able to work any more, I think it'd be nice to be able to have everything where I want it to be. At the moment, I'm trying different games out with the Nintendo 64 Controller (thought it would be interesting), but its analogue stick, which I've been using as a mouse, doesn't have a L3/thumb button. If I were able to set the Z button (L2, according to Retroarch) as the left mouse button, I think I'd be pretty much set. As for the right mouse button, I guess I could set it to one of the other ones.