NLog should use full type name for logger name

When using the nlog logging component, things are logged with just the class name, such as ReactiveObject, CachingMRU, etc.  This makes it hard to create rules to redirect all the ReactiveUI messages anywhere with a rule, as they have no common prefix, etc. using fullname in the nlog GetLogger() call will change this  behavior such that the logger is called ReactiveUI.ReactiveObject, etc, making it possible to filter on ReactiveUI.* or similar