5.6 is no longer allowed to fail.
Fix for #407.
Merge branch '1.7' into 1.8

Conflicts:
	ChangeLog
	lib/Sabre/DAV/Version.php
	lib/Sabre/HTTP/Version.php
Bumped versions
Merge branch '1.8'

Conflicts:
	ChangeLog
	lib/Sabre/DAV/Version.php
	lib/Sabre/HTTP/Response.php
	lib/Sabre/HTTP/Version.php
1.8.8 -> 1.8.9.
Allowing easier overriding of the addressbook home.
XXE security issue.

Issue #414.
Merge branch '1.7' into 1.8

Conflicts:
	ChangeLog
1.8.9 release.
Missing note about sabre/vobject.
Merge branch '1.7' into 1.8
vobject note.
Merge branch '1.8'

Conflicts:
	ChangeLog
	lib/Sabre/DAV/Client.php
Merge branch 'master' of github.com:fruux/sabre-dav
Merge branch 'master' of github.com:fruux/sabre-dav

Conflicts:
	ChangeLog.md
Correctly disabling the external entity loader.
Restoring xml entity loader setting.
Merge branch '1.7' into 1.8

Conflicts:
	ChangeLog
	lib/Sabre/DAV/Version.php
Bumped version.