Added handling for Assembly.GetTypes fail

A ReflectionTypeLoadException gets thrown for a variety of reasons, many of which the indirect caller to this method cares nothing about. If we're going to loop over all assemblies in the AppDomain, we should expect some not to be able to load quite right.

I encountered this I think because an assembly in the appdomain referenced another assembly that wasn't available. Everything runs fine, just don't expect an assembly.GetTypes call to work without exception.