Added option to perform fast-move as a pre-block action (or not). By default fast-move will be done after blocking, but before directory scanning. (CH-223)
Switched row data handling to not use shared pointers nor RowData object to pass information (optimization to slim down the serialization cost) (CH-103).
Adding/retrieving rows (to be serialized) now uses a single method instead of two allowing for simpler code at caller's plase (also a preparation for replacing smart pointer with a reference to real object) (CH-103).