0.6.0

• Allow marking a note as containing HTML. (#17)
• Add languages attribute to skosprovider.skos.ConceptScheme to make it possible to track what languages are being used in a thesaurus. (#19)
• Add a sources attribute to skosprovider.skos.ConceptScheme, skosprovider.skos.Collection and skosprovider.skos.Concept. Every source is an object that currently only has one attribute, a citation. This looks like a good universal common denominator. Just as with notes, a citation may contain HTML. (#20, #24)
• Add sorting to skosprovider.providers.VocabularyProvider.get_all, skosprovider.providers.VocabularyProvider.find, skosprovider.providers.VocabularyProvider.get_top_concepts, skosprovider.providers.VocabularyProvider.get_top_display, skosprovider.providers.VocabularyProvider.get_children_display. Sorting can be done on id, label or sortlabel. The last option makes it possible to introduce arbitrary sorting for concepts, eg. to sort periods chronologically. The sort order can be specified with the sort_order parameter. (#21)
• Remove skosprovider.providers.VocabularyProvider.expand_concept that was deprecated since 0.2.0.
• Fixed a bug with skosprovider.skos.dict_to_label and skosprovider.skos.dict_to_note that would assign None instead of und as the language for labels and notes that have no language.
• Improved checking for valid URIs with e.g. skosprovider.skos.ConceptScheme. This was causing weird issues with registering a provider to the skosprovider.registry.Registry. (#27)