added a cat() function to shutil

modules/lib/shutil.lua

@@ -4,3 +4,8 @@ mkdir=fs.mkdir
 function ls(p)
  for k,v in ipairs(fs.list(p)) do print(v) end
 end
+function cat(p)
+ local f=io.open(p)
+ print(f:read("*a"))
+ f:close()
+end