tool: Allow multiple file/path arguments.
tool: Allow multiple file/path arguments.

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