* M_StartMessages when file loading goes wrong! (Determined by CONS_Alerts of warning level CONS_WARNING and CONS_ERROR happening after W_LoadWadFile has been called.)
* Now actively tries to keep your place on the menu if files are deleted between calls to preparefilemenu().
* More enums! DIR_ (for if you want to try embed more metadata in the dirmenu strings) and REFRESHDIR_ (for refreshing the menu and handling warnings).
* Handle changing size menu between calls to opendir() better.
* Don't crash on draw/enter attempt if one of the dirmenu's is null.
* Moved the addons menu to OP_MainMenu instead of MainMenu for now so it can be tested in MP without needing to mess with several menus.
* Display the amount of space used for serverinfo_pak's fileneeded on the addons menu, both visually and with a percentage.
This is used by Command_Addfile in the MD5 calculation code, so that it can search subfolders properly and allow addfile in netgames to treat them the same way as in SP
Basically this makes sure numwadfiles is updated before loading the SOC/Lua scripts, so if a Lua script calls COM_BufInsertText with the contents "addfile scr_mysticrealm.wad" it can't overwrite the last written wadfile slot! Not that COM_BufInsertText really should be used like that to begin with
