Log Message:
Add emulators/melonds.

melonDS aims at providing fast and accurate Nintendo DS emulation. While it
is still a work in progress, it has a pretty solid set of features:

* Nearly complete core (CPU, video, audio, ...)
* OpenGL renderer, 3D upscaling
* RTC, microphone, lid close/open
* Joystick support
* Savestates
* Various display position/sizing/rotation modes
* (WIP) Wifi: local multiplayer, online connectivity
* and more are planned!