remove THREAD_SAFE ifdefs. from now on, pthreads are required.

additionally we have some explicit init and deinit routines for
core.c now, so that we dont need to share variables with
libproxychains.c.

src/core.h

@@ -28,11 +28,6 @@
 
 #include "ip_type.h"
 
-#ifdef THREAD_SAFE
-#include "mutex.h"
-extern pthread_mutex_t hostdb_lock;
-#endif
-
 /*error codes*/
 typedef enum {
 	SUCCESS=0,
@@ -121,6 +116,9 @@ void proxy_freeaddrinfo(struct addrinfo *res);
 
 void pc_stringfromipv4(unsigned char *ip_buf_4_bytes, char *outbuf_16_bytes);
 
+void core_initialize(void);
+void core_unload(void);
+
 #include "debug.h"
 
 #endif