Vtysh fixes:
* replace -e with -c
* don't save command in history if last line is the same one
* doc/help fixes
diff --git a/doc/vtysh.1 b/doc/vtysh.1
index 30c03c8..7422fa5 100644
--- a/doc/vtysh.1
+++ b/doc/vtysh.1
@@ -19,7 +19,7 @@
 .SH OPTIONS
 
 .TP
-\fB\-e
+\fB\-c
 Specify command to be executed under batch mode.