Temporarily switching to bleed-edge sabre/http until there's a release.
Refactored authentication system to be stateless.
Authentication backends can now specify the reason for failure.
Supporting multiple auth backends.

Fixes #191.
Missing unittests.
ACL plugin no longer relies on $authPlugin->getUserName().
Fixed broken unittests.
Changelog
Merge pull request #582 from fruux/multi-auth

Authentication refactoring
Releasing the first 2.2 alpha.

Switched back to stable sabre/http.
Executable.
Releasing sabredav 2.0.6
Releasing 1.8.11
vobject 2.1.6
Merge branch '1.8' into 2.0

Conflicts:
	ChangeLog
Fixed vobject version dependency.
Merge branch '2.0' into 2.1

Conflicts:
	ChangeLog.md
Updated changelog.
Releasing 2.1.2
Merge branch '2.1'

Conflicts:
	ChangeLog.md