Fix issue with Windows paths
Fix issue with Windows paths

Fixes #1146

pandoraui/traceur-compiler,vicb/traceur-compiler,sebmck/traceur-compiler,vicb/traceur-compiler,rossberg-chromium/traceur-soundscript,google/traceur-compiler,johnjbarton/traceur-compiler,sebgod/traceur-compiler,wilsonokibe/traceur-compiler,sid0818/traceur-compiler,sid0818/traceur-compiler,arv/traceur-compiler,renie/traceur-compiler,google/traceur-compiler,wilsonokibe/traceur-compiler,rossberg-chromium/traceur-soundscript,arv/traceur-compiler,kittens/traceur-compiler,mathiasbynens/traceur-compiler,renie/traceur-compiler,sebmck/traceur-compiler,lintangarief/traceur-compiler,bazaarvoice/traceur-compiler,guybedford/traceur-compiler,kittens/traceur-compiler,bazaarvoice/traceur-compiler,sebgod/traceur-compiler,johnjbarton/traceur-compiler,lintangarief/traceur-compiler,pandoraui/traceur-compiler,longze/traceur-compiler,bjlxj2008/traceur-compiler,bjlxj2008/traceur-compiler,longze/traceur-compiler