All pointer<->integer conversion truncation warnings I'm aware of are
now enabled for MSVC, to hopefully finally get that tool code 64bit-clean.
I had to adjust the idCVar code for this - it should've been safe enough
(highly unlikely that a valid pointer is exactly 0xFFFFFFFF on 64bit),
but triggered those warnings - now it should behave the same as before
but the warnings (which are now errors) are silenced.
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.
