Disable default unicode on windows.
Disable default unicode on windows.

Unless NANODBC_USE_UNICODE is defined, we should disable unicode.
Resolves issue #46.

norsync/nanodbc,mcg1969/nanodbc,ChrisBFX/nanodbc,mcg1969/nanodbc,norsync/nanodbc,nanodbc/nanodbc,ChrisBFX/nanodbc,nanodbc/nanodbc