resource abstract fixes [0.8.1]

This version introduces multiple enhancements:

some fixes for database resource abstract class

Details of additions/deletions below:
--------------------------------------------------------------

Added:      /Lib/Core/Db/Model/Resource/Collection.php

Modified:   /Lib/Core/Db/Model/Resource/Multi/Abstract.php

Modified:   /Lib/Core/Db/Model/Resource/Abstract.php
            -- Updated --
                _executeQuery, clear where variable
                delete, add delete string to query variable
                returnCollection to return empty array if there was no data

Modified:   /Lib/Core/Db/etc/config.ini
            -- Modified --
                changed version from 0.8.0 to 0.8.1