Allow empty dict in dict_from_string
Allow empty dict in dict_from_string

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