Switch tests to new calendar modules.

src/tests.scm

@@ -34,8 +34,8 @@
  (import scheme
 	 listing
 	 util-dict-list
-	 month
-	 period
+	 cal-month
+	 cal-period
 	 util-list
 	 ansi
 	 command-line
@@ -51,8 +51,8 @@
  (define (run-all-tests!)
    (listing-tests!)
    (ldict-tests!)
-   (month-tests!)
-   (period-tests!)
+   (cal-month-tests!)
+   (cal-period-tests!)
    (util-list-tests!)
    (ansi-tests!)
    (command-line-tests!)