[Sass] Add VariableNode#to_sass.
[Sass] Add VariableNode#to_sass.

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