fix FEField.get_data_shape() for surfaces with several facets of a single cell
fix FEField.get_data_shape() for surfaces with several facets of a single cell

vlukes/sfepy,sfepy/sfepy,RexFuzzle/sfepy,BubuLK/sfepy,lokik/sfepy,lokik/sfepy,RexFuzzle/sfepy,sfepy/sfepy,vlukes/sfepy,RexFuzzle/sfepy,rc/sfepy,lokik/sfepy,lokik/sfepy,BubuLK/sfepy,RexFuzzle/sfepy,vlukes/sfepy,BubuLK/sfepy,sfepy/sfepy,rc/sfepy,rc/sfepy