- entries are buffered and written as stream with many entries at once (saves many IO accesses)
- entries are compressed with gzip: increases capacity of cache
- concurrency for stream-writing and compression: all writings to the cache are non-blocking
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@5284 6c8d7289-2bf4-0310-a012-ef5d649a1542