This removes a dependency inversion between core and common. It's also
the proper place for the file since it makes screen layout decisions
specific to the 3DS.
1. removed zl, zr and c-stick from HID::PadState. They are handled by IR, not HID
2. removed button handling in EmuWindow
3. removed key_map
4. cleanup #include
Corrects a few issues with regards to Doxygen documentation, for example:
- Incorrect parameter referencing.
- Missing @param tags.
- Typos in @param tags.
and a few minor other issues.
Yuri Kunde Schlesner