2015-06-23: examples/cli: distinguish between empty program call and commandline

examples/cli: distinguish between empty program call and commandline arguments

diff --git a/examples/cli.w b/examples/cli.w
--- a/examples/cli.w
+++ b/examples/cli.w
@@ -9,6 +9,8 @@ define-module : examples cli
 define : main args
          match args
            : prog ; just the program name, empty call
+             display : car args
+           else
              display args
          newline