Callbacks in node style

And added some test for it as well.
A lot of them fails but I think that is as it should be. There is a error somewhere.
Things like setNameSync works but not setName or at least it does not work in the sense that I'm able to retrieve the new name within the callback. It will be written to the tellstick.conf.

When running the tests, please observe that I try to clean up tellstick.conf afterwards but it might screw it up completely so please have a backup :)

This closes #15