blockgen.py: split main() into new gen_block(), add_args()
blockgen.py: split main() into new gen_block(), add_args()

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