v0.4.4

Highlights

• WebDAV-Push support — notify subscribed clients of collection changes.
• icalendar: reject and normalize empty VTIMEZONE blocks.
• Accept a non-zero Depth header for addressbook-multiget reports (#692).
• Return 412 Precondition Failed when a pre_put_hook raises a precondition failure.
• Handle OutOfSpace more gracefully.
• web: apply the SCRIPT_NAME prefix to the schedule-default-calendar URL.
• caldav: don't path-quote scheme URIs in calendar-user-address-set.
• web: only fall back to the EMAIL environment variable in single-user mode.

Full changelog: v0.4.3...v0.4.4