fix(data): Data property changes not applied to internal data structure. LoadData call causes short loop.

When calling loadData a short loop is created because the rowManager will change the data property which then will call loadData again. Additionally changes in the order of the data model are not reflected into the internal data structure affecting sorting by drag&drop. To prevent those and other issues loadData, removeData and clearData use now the data property. Thus the data property is the "master" of all data management and no loops are possible anymore.  Since this is not very efficient (copy data into data property and copy data to internal structure) all three functions are marked as deprecated. Either they can be removed in the future or be used as convenient functions.