NEW: RSSCache without refresh thread
NEW: backup
NEW: RSSCache with no thread in background
NEW: renamed old ResourceStatus to ResourceStatusOldCache, and set new
one as ResourceStatus.
FIX: added ramdomized 20% extra to cache lifetime.
Merge pull request #1365 from ubeda/DEV_v6r7_RSSCacheNoThread

[v6r7] DEV: RSSCache without thread in background ( Needs certification ! )