Add internal configuration file, add missing includes, rename some options

src/thread_win.c

@@ -187,7 +187,7 @@ int bh_semaphore_try_wait(bh_semaphore_t *semaphore)
     return BH_OK;
 }
 
-#if WINVER >= _WIN32_WINNT_VISTA
+#if WINVER >= _WIN32_WINNT_VISTA && !defined(BH_THREADS_WINXP)
 int bh_cond_init(bh_cond_t *cond)
 {
     InitializeConditionVariable(&cond->handle);