correctly internalize slices (fixes #7)
correctly internalize slices (fixes #7)

jargv/gopherjs,jargv/gopherjs,Yanjing123/gopherjs,flimzy/gopherjs,nmfzone/gopherjs,jeremyschlatter/gopherjs,ebroder/gopherjs,albrow/gopherjs,ebroder/gopherjs,gopherjs/gopherjs,Archs/gopherjs,bpowers/gopherjs,govlas/gopherjs,gopherjs/gopherjs,nmfzone/gopherjs,Archs/gopherjs,roth1002/gopherjs,roth1002/gopherjs,Yanjing123/gopherjs,jargv/gopherjs,Archs/gopherjs,flimzy/gopherjs,bpowers/gopherjs,roth1002/gopherjs,ebroder/gopherjs,jeremyschlatter/gopherjs,albrow/gopherjs,bpowers/gopherjs,jeremyschlatter/gopherjs,nmfzone/gopherjs,flimzy/gopherjs,gopherjs/gopherjs,govlas/gopherjs,gopherjs/gopherjs,gopherjs/gopherjs,rasata/gopherjs,albrow/gopherjs,Yanjing123/gopherjs,rasata/gopherjs,govlas/gopherjs,rasata/gopherjs