(svn r2809) Implement more generic threading functions, which allow more than one thread

thread.h

@@ -0,0 +1,19 @@
+/* $Id$ */
+
+#ifndef THREAD_H
+#define THREAD_H
+
+/*
+ * DO NOT USE THREADS if you don't know what race conditions, mutexes,
+ * semaphores, atomic operations, etc. are or how to properly handle them.
+ * Ask somebody who has a clue.
+ */
+
+typedef struct Thread Thread;
+
+typedef void (*ThreadFunc)(void*);
+
+Thread* OTTDCreateThread(ThreadFunc, void*);
+void    OTTDJoinThread(Thread*);
+
+#endif