msh: create testsuite (based on hush one)

hush: add TODO (doesn't know ":" command)

shell/msh_test/msh-execution/nested_break.right

@@ -0,0 +1,8 @@
+A
+B
+iteration
+C
+A
+B
+iteration
+D

shell/msh_test/msh-execution/nested_break.tests

@@ -0,0 +1,17 @@
+# Testcase for http://bugs.busybox.net/view.php?id=846
+
+n=0
+while :
+do
+        echo A
+        while :
+        do
+    		echo B
+                break
+        done
+        echo iteration
+        [ $n = 1 ] && break
+	echo C
+        n=`expr $n + 1`
+done
+echo D