LanguageMachines/libfolia: v1.10

Major Release, implementing FoLiA spec 1.5 added text checking for all 1.5 documents and up added offset and ref checking for Text in all 1.5 documents and up 'empty' text inside TextContent, PhonContent and Textmarkup is significant better version checking text checking can be dis/enabled using FOLIA_TEXT_CHECK environment variable added submetadata mechanism implemented aliases for annotation setnames added an xmlstring() serializer for Document bug fixes: in LineBreak serializing XmlComment is textless. miscellaneous small fixe