Fix presets loader
Fix presets loader

- Add reset all glyphs before seeding data
- Add comments about internal structure

fontello/fontello,katgironpe/fontello,bartuspan/fontello,fontello/fontello,CapeSepias/fontello,vinod1988/fontello,cnbin/fontello,modulexcite/fontello,bartuspan/fontello,katgironpe/fontello,asrin475/fontello,Sivalingaamorthy/fontello,cnbin/fontello,bartuspan/fontello,blackgirl/fontello,cnbin/fontello,marcia-kubik/fontello,liguangmings/fontello,Sivalingaamorthy/fontello,liguangmings/fontello,SKing7/fontellomt,katgironpe/fontello,vinod1988/fontello,marcia-kubik/fontello,liguangmings/fontello,SKing7/fontellomt,fontello/fontello,blackgirl/fontello,vinod1988/fontello,marcia-kubik/fontello,blackgirl/fontello,Sivalingaamorthy/fontello,CapeSepias/fontello,asrin475/fontello,modulexcite/fontello,modulexcite/fontello,CapeSepias/fontello,asrin475/fontello