[syslinux] Complex Menu update

[Murali Krishnan Ganapathy]

Starting with 3.20-pre6 there is a script included which generates the C 
code to create the complex menu from a ".menu file". You can specify 
menus and submenus, user authentication, user permissions, context 
sensitive help and the like using just the .menu file. Check out the 
"test.menu" and "test2.menu" in the "menu" subdirectory for examples. 
Since this has not been tested heavily (only tested with the provided 
sample files), please create your own .menu files and let me know of any 
bugs.

- Murali