A few keycode/scancode renaming suggestions

[Sackzement]

SDLK_a-SDLK_z -> SDLK_A-SDLK_Z (uppercase)

SDL_SCANCODE_NUMLOCKCLEAR -> SDL_SCANCODE_KP_NUMLOCK (adding _KP, removing CLEAR)

SDL_SCANCODE_AGAIN -> SDL_SCANCODE_REDO

RIGHT/LEFT vs L/R:

SDL_SCANCODE_LCTRL
SDL_SCANCODE_LSHIFT
SDL_SCANCODE_LALT
SDL_SCANCODE_LGUI
SDL_SCANCODE_RCTRL
SDL_SCANCODE_RSHIFT
SDL_SCANCODE_RALT
SDL_SCANCODE_RGUI
SDL_SCANCODE_LEFTBRACKET   -> SDL_SCANCODE_LBRACKET
SDL_SCANCODE_RIGHTBRACKET  -> SDL_SCANCODE_RBRACKET
SDL_SCANCODE_KP_LEFTPAREN  -> SDL_SCANCODE_KP_LPAREN
SDL_SCANCODE_KP_RIGHTPAREN -> SDL_SCANCODE_KP_RPAREN
SDL_SCANCODE_KP_LEFTBRACE  -> SDL_SCANCODE_KP_LBRACE
SDL_SCANCODE_KP_RIGHTBRACE -> SDL_SCANCODE_KP_RBRACE

RETURN vs ENTER:

SDL_SCANCODE_KP_ENTER
SDL_SCANCODE_RETURN   -> SDL_SCANCODE_ENTER

PERIOD vs DOT:

SDL_SCANCODE_PERIOD    -> SDL_SCANCODE_DOT
SDL_SCANCODE_KP_PERIOD -> SDL_SCANCODE_KP_DOT

SDL_SCANCODE_DISPLAYSWITCH -> SDL_SCANCODE_SWITCHVIDEOMODE

A bit of clarification needed:

SDL_SCANCODE_APPLICATION
SDL_SCANCODE_APP1
SDL_SCANCODE_APP2

Shorten some names: SDL_SCANCODE_ESCAPE -> SDL_SCANCODE_ESC SDL_SCANCODE_PRINTSCREEN -> SDL_SCANCODE_PRINT SDL_SCANCODE_CALCULATOR -> SDL_SCANCODE_CALC SDL_SCANCODE_MEDIASELECT -> SDL_SCANCODE_MEDIA