DAV: Single-type calendar and tasks folders
Summary:
- Don't store tasks and events in the same folder, set new folder supported-calendar-component-set appropriately
- Make single request on folder creation. Before it was MKCOL + PROPPATCH, now it's MKCOL
Test Plan: Create Tasks folder, check it does not appear in Calendar, and vice-versa
Reviewers: Roundcube Developers, mollekopf
Reviewed By: Roundcube Developers, mollekopf
Subscribers: Roundcube Developers
Differential Revision: https://git.kolab.org/D4656