allowing selector-lists to have superfluous commas
allowing selector-lists to have superfluous commas

mtwebster/mint-libsass,mikebarkas/libsass,saper/libsass,FishingCactus/libsass,mikebarkas/libsass,FishingCactus/libsass,webdev1001/libsass,FishingCactus/libsass,moovweb/libsass,mikebarkas/libsass,errorx666/libsass,panicinc/libsass,mikebarkas/libsass,moovweb/libsass,moovweb/libsass,panicinc/libsass,technoAri/libsass,FishingCactus/libsass,panicinc/libsass,am11/libsass,webdev1001/libsass,khchanel/libsass,TBAPI-0KA/NSass,mtwebster/mint-libsass,technoAri/libsass,errorx666/libsass,admire93/libsass-python,saper/libsass,saper/libsass,khchanel/libsass,khchanel/libsass,panicinc/libsass,TBAPI-0KA/NSass,errorx666/libsass,webdev1001/libsass,dahlia/libsass-python,mtwebster/mint-libsass,admire93/libsass-python,moovweb/libsass,TBAPI-0KA/NSass,TBAPI-0KA/NSass,mtwebster/mint-libsass,technoAri/libsass,TBAPI-0KA/NSass,am11/libsass,technoAri/libsass,am11/libsass,mtwebster/mint-libsass,panicinc/libsass,mikebarkas/libsass,khchanel/libsass,saper/libsass,webdev1001/libsass,technoAri/libsass,webdev1001/libsass,saper/libsass,khchanel/libsass,TBAPI-0KA/NSass,am11/libsass,am11/libsass,FishingCactus/libsass,errorx666/libsass,dahlia/libsass-python