• #784: Sync logs for address books were not correctly cleaned up after
  deleting them.
• #787: Cannot use non-seekable stream-wrappers with range requests.
• Faster XML parsing and generating due to sabre/xml update.
• The zip release ships with sabre/vobject 3.5.0,
  sabre/http 4.2.1, sabre/event 2.0.2,
  sabre/uri 1.1.0 and sabre/xml 1.4.1.