Implement ffserver -version.

Patch by: Stefano Sabatini, stefano.sabatini-lala poste it

Originally committed as revision 13234 to svn://svn.ffmpeg.org/ffmpeg/trunk

doc/ffserver-doc.texi

@@ -196,6 +196,8 @@ ffserver [options]
 @section Options
 @c man begin OPTIONS
 @table @option
+@item -version
+Show version.
 @item -L
 Print the license.
 @item -h

ffserver.c

@@ -4349,6 +4349,7 @@ static void opt_show_help(void)
 
 static const OptionDef options[] = {
     { "h", OPT_EXIT, {(void*)opt_show_help}, "show help" },
+    { "version", OPT_EXIT, {(void*)show_version}, "show version" },
     { "L", OPT_EXIT, {(void*)show_license}, "show license" },
     { "n", OPT_BOOL, {(void *)&no_launch }, "enable no-launch mode" },
     { "d", 0, {(void*)opt_debug}, "enable debug mode" },