[Sass] Make Sass::Plugin.update_stylesheets work under 1.9.
[Sass] Make Sass::Plugin.update_stylesheets work under 1.9.

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