The code used #ifdef __ppc__, probably a leftover from old Mac support,
which apparently doesn't work on all PPC systems (maybe not 64bit PPC).
Now using the LittleFloat() function instead which exists for
exactly this purpose and already handles endianess properly.
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.
