Cpuid improvement

Fix for bug 4445. Implemented cpuid based core identification for Intel processors. 
This was the code before my change, I just changed the way the static "cores" variable was computed. Should I remove it ?

Comment was there before. Will clarify it, for me it was a reminder that this function is not about physical processors, but about physical cores. The naming of cores/processor/virtual core can be misleading so there should be some additional explanation of what it is meant by each one.