all cpu-related stuff is now defined in cpu.h (with cpu_ prefix and
fully encapsulated). fix quite brittle core/HT unit/package detection.
implement mkdir on VC8, where it is deprecated
add strdup on MacOSX
move ia32 code into separate subdir. functions implemented in asm are
called ia32_asm_*.
add some unix versions of sysdep functions (cannot test them)
timer: fix for amd64 linux
This was SVN commit r4995.
