Compiling db-lib using Visual C++ 2005 Express

To compile library which uses TryEnterCriticalSection function, we must
define *_WIN32_WINNT* as 0x0400 or later.

Update some define in win32/config.h

Make configure script generate win32/config.h to update the VERSION in it.

Initial patches from Ladislav Karrach, edited by me (Frediano Ziglio)