[plt-scheme] SrPersist and libiodbc 3.51.1

I was trying to reinstall SrPersist on my OS X 10.2 machine and found a 
small snag: for some reason, the version of libiodbc that was installed 
through Fink was not working, so I went looking for a more recent 
version and found a prebuilt v3.51.1 at this URL:

     http://oplweb.openlinksw.com/product/webmatrixsdk.asp

But the sql.h in this more recent version defines the LPWSTR and WCHAR 
types, which conflicted with the dummy declarations at the top of 
srpersist.cxx, so I had to comment those out. Are they necessary? Or 
could they be guarded so they don't generate this conflict when they 
are defined?

Thanks,
Dave