set bmxd version to 0.6 (0.5 is used on server, which is still very old and...
- set bmxd version to 0.6 (0.5 is used on server, which is still very old and supports two way tunnel)
- replace awful implementation of list handling with ObjectList (-6kbyte binary size)
- fix some memory leaks (valgrind)
todo: remove tunnel option code, because it is not used any more (we have only one way tunnel)