Fix option names in tor-fw-helper manpage

fix for bug 7768

changes/bug7768

@@ -0,0 +1,3 @@
+  o Documentation fixes:
+    - Update tor-fw-helper.1.txt to describe its options with their
+      correct names. Fixes bug 7768.

doc/tor-fw-helper.1.txt

@@ -15,8 +15,7 @@ tor-fw-helper - Manage upstream firewall/NAT devices
 SYNOPSIS
 --------
 **tor-fw-helper** [-h|--help] [-T|--test] [-v|--verbose] [-g|--fetch-public-ip]
- -i|--internal-or-port __TCP port__ [-e|--external-or-port _TCP port_]
- [-d|--internal-dir-port _TCP port_] [-p|--external-dir-port _TCP port_]
+ [-p __external port__:__internal_port__]
 
 DESCRIPTION
 -----------
@@ -31,7 +30,7 @@ OPTIONS
 **-h** or **--help**::
     Display help text and exit.
 
-**-v**::
+**-v** or **--verbose**::
     Display verbose output.
 
 **-T** or **--test**::
@@ -41,8 +40,9 @@ OPTIONS
 **-g** or **--fetch-public-ip**::
     Fetch the the public ip address for each supported NAT helper method.
 
-**-p** or **--forward-port** __external_port__:__internal_port__::
-    Forward external_port to internal_port.
+**-p** or **--port** __external_port__:__internal_port__::
+    Forward external_port to internal_port.  This option can appear
+    more than once.
 
 BUGS
 ----