Fix#2442. Although data and styles are handled correctly after removing row(s) or column(s), the dimensions of the removed rows and columns remain behind to afflict their replacements. This PR will take care of removing the dimensions as well.
Dimensions has a _clone method for a deep clone, but all of its properties, as well as the properties of RowDimensions and ColumnDimensions, are scalars, and do not require a deep clone. The method is deleted.
oleibman