Add support for optionally choosing from a list of control mappings for each launcher

[bmcclure]

For some games, you need to remap keys, map mouse buttons to keyboard keys, map a game controller to work with games that don't support one, etc. You can sometimes do this elsewhere, but for cases where that isn't enough, Launchpad should allow extensive key mapping and hotkey support.

You should be able to create profiles in which you can:

• Remap keyboard keys, controller buttons, mouse buttons, joysticks, etc so that they emulate any other type of control
• Select from existing common controller mappings
• Choose a hotkey in Launchpad's settings that, when pressed, will overlay your current mapping