Getting closer (but not yet there) to being able to compile under VC6
again.  Removed the following subprojects and folded them into pythoncore,
to match what's being done under VC7.  We *can* build the core DLL
under VC6 again after this:

datetime.dsp
winreg.dsp
parser.dsp
_sre.dsp
_csv.dsp
mmap.dsp
_symtable.dsp
10 files changed