Hidden pacakges changed to now show in the list.
Removed unused function.

Since all cache items are stored under the same directory based on the
relative path from the game data directory to the cached item, the
Get_Use_Imgcache_Path is not needed.
Savegames now saved to subdirectory for packages.

When playing a package, screenshots and savegames are stored in a
subdirectory of the usual directory.