If a key is pressed whichs SDL_Keycode isn't known to Doom3 (has no
corresponding K_* constant), its SDL_Scancode is mapped to the
corresponding newly added K_SC_* scancode constant.
I think I have K_SC_* constants for all keys that differ between
keyboard layouts (which is mostly printable characters; F1-F12, Ctrl,
Shift, ... should be the same on all layouts, which means that e.g.
SDL_SCANCODE_F1 always belongs to SDLK_F1 which the old code already
maps to Doom3's K_F1).
What's extra nice (IMO) is that when Doom3 requests a *localized* name
of the key (like for showing in the bindings menu), we actually use the
name of the SDL_Keycode that *currently* belongs to the scancode, and
esp. the "Western High-ASCII characters" (ISO-8859-1) supported by Doom3
like Ä or Ñ are displayed correctly.
(I already implemented a very similar hack in Yamagi Quake II and
reused the list of scancodes)
This should fix most of the problems reported in #323
Don't include the lazy precompiled.h everywhere, only what's
required for the compilation unit.
platform.h needs to be included instead to provide all essential
defines and types.
All includes use the relative path to the neo or the game
specific root.
Move all idlib related includes from idlib/Lib.h to precompiled.h.
precompiled.h still exists for the MFC stuff in tools/.
Add some missing header guards.
