added fs.cp and fs.mv for copying amd moving files.

modules/lib/fs.lua

@@ -121,3 +121,14 @@ function fs.cd(p)
   error("non-existent/not a dir")
  end
 end
+function fs.cp(s,d)
+ local df = fs.open(d,"wb")
+ local sf = fs.open(s,"rb")
+ fs.write(df,fs.readall(sf))
+ fs.close(df)
+ fs.close(sf)
+end
+function fs.mv(s,d)
+ fs.cp(s,d)
+ fs.rm(s)
+end