[Sass] Add equality and hashing to selectors.
[Sass] Add equality and hashing to selectors.

Galactix/sass,liquidmetal/sass,briangonzalez/sass,saper/sass,zaru/sass,ridixcr/sass,tenderlove/sass,chriseppstein/haml,amatsuda/haml,cmpereirasi/sass,chriseppstein/haml,stewx/sass,rammy7219/sass,StephanieMak/sass,ridixcr/sass,schneems/sass,14113/sass,dg1dd1ngs/haml,cmpereirasi/sass,macressler/haml,baiyanghese/sass,Iamronan/sass,HugoRLopes/sass,haml/haml,chriseppstein/sass,OrenBochman/sass,nazar-pc/haml,JuanitoFatas/sass,keithpitty/haml,haml/haml,Iamronan/sass,keithpitty/haml,stanhu/haml,oss-practice/sass,Nzaga/sass,Industrys/sass,dylannnn/sass,rammy7219/sass,askl56/sass,srinivashappy/sass,xzyfer/sass,hcatlin/sass,hcatlin/sass,Ahnita/sass,macressler/haml,srinivashappy/sass,haml/haml,jaroot32/sass,Nzaga/sass,zaru/sass,nickg33/sass,Anshdesire/sass,lmetla/sass,nicklima/sass,PMArtz92/sass,haml/haml,DanteKaris/sass,srawlins/sass,nicklima/sass,antonifs/sass,nazar-pc/haml,nickg33/sass,OrenBochman/sass,HugoRLopes/sass,tangposmarvin/haml,PMArtz92/sass,Andrey-Pavlov/sass,Anshdesire/sass,concord-consortium/haml,Galactix/sass,amitsuroliya/sass,lmetla/sass,danielfein/sass,jaroot32/sass,tangposmarvin/haml,JuanitoFatas/sass,xzyfer/sass,dylannnn/sass,MetaAshley/sass,uniba/hamldoc_ja,tangposmarvin/sass,stanhu/haml,MetaAshley/sass,schneems/sass,Andrey-Pavlov/sass,antonifs/sass,liquidmetal/sass,saper/sass,tangposmarvin/sass,modulexcite/sass,StephanieMak/sass,stewx/sass,dg1dd1ngs/haml,DanteKaris/sass,sideci-sample/sideci-sample-haml,amitsuroliya/sass,srawlins/sass,askl56/sass,Ahnita/sass,Industrys/sass,danielfein/sass,modulexcite/sass