band_gaps_he: new AcousticBandGapsApp.plot_band_gaps()
band_gaps_he: new AcousticBandGapsApp.plot_band_gaps()

- update .process_options(), .call()

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