New method DefaultModel::setPropertyRaw() to initialize the models properly.

Before, there was an issue that models were always marked as "changed",
as the setProperty() method used by the data provider always detected a
change from null => $value.
Remove obsolete getDC() and setDC() methods from DefaultController.
Remove obsolete methods DefaultController::calcLabelPattern() and DefaultController::calcNeededFields().
New methods DefautlController::assembleSiblingsFor(), searchParentOf(), searchParentOfIn().
Get rid of obsolete implementation of cut() and copy() in DefaultController.

The methods are not needed anymore and broken. Logic now resides in the
view.
Cleanup.
Remove method DefaultController::generateAjaxPalette() - not used anymore.
Remove obsolete method DefaultController::insertCopyModel().
Remove obsolete method DefaultController::reorderSorting().
Remove obsolete method DefaultController::getNewPosition().
New method DefaultController::createClonedModel().
New method DefaultController::sortInto() for updating the sorting properties in manual sort.

The method has to be refactored to reduce complexity though.
New method DefaultController::pasteAfter().
Fix the cut and paste URIs in BaseView.
New method BaseView::getManualSortingProperty().
New method BaseView::getModelsFromClipboard().
Implement BaseView::paste() and BaseView::cut().

paste() is not finished yet though.
Refactor DefaultController::sortInto() into new class SortingManager.
Clone the data container prior to setting it in the environment.
Fix cloning in DefaultContainer.