added include/caldav.php based on include/caldav-client-v2.php,
but with cURL mechanics borrowed from (former) include/carddav.php
only load backends that are actually used in BackendCombined
fixed indentation
'rootcreatefolderbackend' should be one of the 'folderbackend's anyway - surplus condition removed
(hopefully) clarified license
made use of ZLog facility
fixed URL handling
Merge git://github.com/fmbiete/Z-Push-contrib

Conflicts:
	backend/combined/combined.php
	backend/ldap/config.php
Merge pull request #43 from tkoester/master

Rework caldav-client to use CURL library. Thanks @tkoester!