no pass by ref for objects
Improves some PHPDocs
add CHECKACL() function

Checks hidden pages and acl rights.
sqlite 3 has no close function, unset the PDO object
close PDOstatements in unittests

close PDOStatement object when in a state of having unfetched rows.
Improve PHPDocs and error handling
Merge pull request #23 from Klap-in/aclsupport

ACL and hidden pages support