create Collection class (issue #4)
create Collection class (issue #4)

This version introduces multiple enhancements:

 loop by pages handling added

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

Modified:   Data/Collection.php
            -- Added --
                _getIndexesToUpdate return list of indexed to update or delete when iterating by pages
            -- Updated --
                offsetExists loop by pages handling added
                offsetGet loop by pages handling added
                offsetSet loop by pages handling added
                offsetUnset loop by pages handling added
                current loop by pages handling added
                key loop by pages handling added
                next loop by pages handling added
                rewind loop by pages handling added
                valid loop by pages handling added
                loopPages renamed to loopByPages

bluetree-service/data,chajr/class-kernel,chajr/class-kernel,bluetree-service/container,bluetree-service/collection