script/gen_gallery.py: simplify section titles, generate better labels
script/gen_gallery.py: simplify section titles, generate better labels

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