Adding mini module system.

common/modules_tests.fs

@@ -0,0 +1,29 @@
+\ Copyright 2022 Bradley D. Nelson
+\
+\ Licensed under the Apache License, Version 2.0 (the "License");
+\ you may not use this file except in compliance with the License.
+\ You may obtain a copy of the License at
+\
+\     http://www.apache.org/licenses/LICENSE-2.0
+\
+\ Unless required by applicable law or agreed to in writing, software
+\ distributed under the License is distributed on an "AS IS" BASIS,
+\ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+\ See the License for the specific language governing permissions and
+\ limitations under the License.
+
+needs modules.fs
+
+e: test-modules
+  vocabulary foo   foo definitions
+  : a ;
+  internal
+    : b ;
+  external
+    : c b ;
+  module
+  : d ;
+  vlist
+  forth definitions
+  out: d c  a  
+;e