2017-02-17: export some procedures

export some procedures

diff --git a/examples/ensemble-estimation.w b/examples/ensemble-estimation.w
--- a/examples/ensemble-estimation.w
+++ b/examples/ensemble-estimation.w
@@ -34,6 +34,7 @@ exec guile -L $(dirname $(dirname $(real
 ;;     x'^a = x'^b - αK·H(x'^b)
 
 define-module : examples ensemble-estimation 
+              . #:export : EnSRF H standard-deviation-from-deviations make-covariance-matrix-with-offdiagonals-using-stds
 use-modules : srfi srfi-42 ; list-ec
               srfi srfi-9 ; records
               oop goops ; generic functions