could we cache the template httplistings?

[guillep]

Launcher 3.1.1-418-ge2eb5da2

Every time I click on an HTTP listing it takes a looot of time.
This is of course the fault of the server that has a lot of latency, but the launcher could be more intelligent here:

• cache the listing
• refresh it every X time
• force a way to kill the cache (or just document to do it by removing some file from the file system) should be enough