allow more metadata / types of files

[abma]

http://springrts.com/phpbb/viewtopic.php?p=522676#p522676

type: game/map/mod/dev tool
advertising url/html page: main page for the package, which may include media such as images, youtube/video links; would primarily be used to advertise the game/map or w/e to people who don't have it
page hierarchy: list/graph of pages that can be used by the lobby to display concrete "game" tabs, f.e having subpages such as "planetwars" "matchmaking", "news" in the zero-k page hierarchy part of the rapid package
etc...