WIP: Locale input

keyboardlocale: Enables receiving text input from SDL_TEXTINPUT events. Text input fields (console, chat, some menu fields) will accurately follow the keyboard's layout.
usekeycodes: Uses keycodes (the key arrangement on a keyboard) instead of scancodes (the data transmitted by keyboard). Not entirely accurate.
forceqwerty: Forces a QWERTY layout (instead of QWERTZ or AZERTY - did not test with Dvorak.) Does not work with textinput, only keyboardlocale.