The defines in idlib/Str.h won't be set to redirect the low
level c string functions to idStr when IDSTR_NO_REDIRECT is
set.
Fixes compilation for MSVC:
error C2761: 'Cmp' : member function redeclaration not allowed
Reported by spiral.
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.
