Feature request: Keep catalogue cache

[narcisgarcia]

When user enters to a movies / TVShow / etc. list, PopcornTime downloads a fresh list with thumbnails and other metadata.
If user exits and asks for it again (although in 5 minutes), PopcornTime downloads whole list from scratch again. This results in a really a slow behaviour on slow machines and with slow internet accesses.

• This cache duration could be an additional setting to be customized, in minutes, hours or days of live.