Consolidate webdav code - move all to one app

.gitignore

apps/dav/appinfo/info.xml

apps/dav/appinfo/v1/publicwebdav.php

apps/dav/appinfo/v1/webdav.php

apps/dav/lib/connector/publicauth.php

apps/dav/lib/connector/sabre/appenabledplugin.php

apps/dav/lib/connector/sabre/auth.php

apps/dav/lib/connector/sabre/blocklegacyclientplugin.php

apps/dav/lib/connector/sabre/copyetagheaderplugin.php

apps/dav/lib/connector/sabre/custompropertiesbackend.php

apps/dav/lib/connector/sabre/directory.php

apps/dav/lib/connector/sabre/dummygetresponseplugin.php

apps/dav/lib/connector/sabre/exception/entitytoolarge.php

apps/dav/lib/connector/sabre/exception/filelocked.php

apps/dav/lib/connector/sabre/exception/invalidpath.php

...av/lib/connector/sabre/exception/unsupportedmediatype.php

apps/dav/lib/connector/sabre/exceptionloggerplugin.php

apps/dav/lib/connector/sabre/file.php

apps/dav/lib/connector/sabre/filesplugin.php

apps/dav/lib/connector/sabre/listenerplugin.php