mmap and mprotect are used in non-Windows instead of VirtualAlloc

pointer calculation fixed for 64 bit compatibility.
64 bit function works on Windows and Mac
32 bit Mac stdcall still not implemented

git-svn-id: http://python4delphi.googlecode.com/svn/trunk@85 e41fde0b-5a56-0410-8151-d5964863ceb2

Author: [email protected]