Fixed vcardurl field length.
Merge branch '1.6' into 1.7

Conflicts:
	ChangeLog
	examples/sql/pgsql.principals.sql
	lib/Sabre/DAV/Version.php
	lib/Sabre/DAVACL/Version.php
Merge branch '1.7' into 1.8

Conflicts:
	ChangeLog
	lib/Sabre/DAV/Version.php
	lib/Sabre/DAVACL/Version.php