fixes to stack trace code under x64 (from work):

- displaying symbol values requires stack pointer, not frame pointer
- update debug_IsPointerBogus
- skip-n-frames code changed to skip-all-frames-up-to-func (more
reliable in the face of inlining)

debug.cpp: cleanup

This was SVN commit r6410.

source/network/SocketBase.cpp

@@ -221,7 +221,7 @@ void CSocketBase::Shutdown()
 
 void *WaitLoopThreadMain(void *)
 {
-	debug_set_thread_name("net_wait");
+	debug_SetThreadName("net_wait");
 
 	GLOBAL_LOCK();
 	CSocketBase::RunWaitLoop();