Give fields in event_t better names

src/am_map.c

src/console.c

src/d_event.h

src/d_main.c

src/f_finale.c

src/g_game.c

src/g_input.c

src/hu_stuff.c

src/lua_inputlib.c

src/m_cheat.c

src/m_menu.c

src/m_misc.c

src/sdl/i_system.c

src/sdl/i_video.c

src/win32/win_main.c

src/win32/win_sys.c