fix EVolumeDotTerm for scalar material and vector variables
fix EVolumeDotTerm for scalar material and vector variables

rc/sfepy,vlukes/sfepy,sfepy/sfepy,sfepy/sfepy,vlukes/sfepy,rc/sfepy,vlukes/sfepy,sfepy/sfepy,BubuLK/sfepy,BubuLK/sfepy,rc/sfepy,BubuLK/sfepy