The code around errcode is definitly messy. In CVS now, it actually
renames *our* errcode() function to __msvc_errcode, and exports this
from postgres.exe. This is definitly very borken.
The check for _MSC_VER > 1400 won't come true until Microsoft releases
the next verison of Visual Studio - VS2005 is 1400, not >1400.
Attached patch fixes this. Tested on MSVC and on Mingw.
//Magnus
