WiP - Make use of djang-simple-menus

Rearchitect menu as such (One menu (main) with one MenuItem per app with ``children`` generated from function)
main
 \ Characters
 |  \ [List of characters]
 |  \ [Functions]
 \ Skills
 \ Plans
 |  \ [List of plans]
 |  \ [Functions]
 \ Profile [Dynamic Title]
    \ [Functions]