* Implemented the handling of values === NULL in Queries; related to #3838 (needs feed-back)
* Changed all calls to t3lib_div::makeInstance('Tx_Extbase_Persistence_Manager') to Tx_Extbase_Dispatcher::getPersistenceManager()
* Fixed conversion of DateTime objects in Query values
* Eliminated unnecessary braces
* Fixed "NOT" ( from "(NOT foo='bar')" to "NOT (foor='bar')" )