2016-04-06: safepassword: remove + as delimiter, since it’s not on the base

safepassword: remove + as delimiter, since it’s not on the base layer on US keyboards

diff --git a/examples/safepassword.w b/examples/safepassword.w
--- a/examples/safepassword.w
+++ b/examples/safepassword.w
@@ -28,9 +28,9 @@ define : password length
       let
        : quertysafeletters "0123456789ABCDEFGHJKLMNPQRSTUVWXabcdefghijkmnopqrstuvwx"
          ;; that’s newbase60 without yz_
-         ;; means 5.78 bits entropy per letter.
-         delimiters ",.!?-+"
-         ;; that’s 2.5 bits entropy per delimiter
+         ;; means 5.78 bits of entropy per letter.
+         delimiters ",.!?-"
+         ;; that’s 2.32 bits of entropy per delimiter
        let fill
          : letters '()
            remaining length