fix create_task_dof_maps() for single task, clean up
fix create_task_dof_maps() for single task, clean up

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