#130 refactor: docs and internal structure of TypeCatalogue
#130 refactor: moved type loading from TypeCatalogue constructor to Load() method
#130 red: added TypeCatalogueTests.Should_warn_of_bad_assembly_files
#130 green: satisfied TypeCatalogueTests.Should_warn_of_bad_assembly_files
#130 added warnings when failing to load assembly or types
#130 refactor: refactored TypeCatalogueTests