Better debug output for WlcView and WlcOutput

[Timidger]

We should list the class and title information for a view, if they are available, as well as the WlcView handle number. It would really help debugging to know which window was associated with which handle and that's either very hard or very impossible to do without this information in the logs.

We need to handle the case where a View is invalid however, and return specifically that the view is invalid (e.g: trying to call one of these methods return null or something)