2016-10-10: export the required functions and macros to use enter-three-witches three-witches-space-in-name

export the required functions and macros to use enter-three-witches from outside

diff --git a/examples/enter-three-witches.w b/examples/enter-three-witches.w
--- a/examples/enter-three-witches.w
+++ b/examples/enter-three-witches.w
@@ -4,6 +4,7 @@ exec guile -L $(dirname $(dirname $(real
 ; !#
 
 define-module : examples enter-three-witches
+    . #:export : introduced-names ->string show colortable color say-words say-name say Speak Speak-indirect Enter
 
 use-modules : ice-9 optargs
               srfi srfi-1