Progress bar cosmetics

Do not print line when nothing was transferred or skipped. Fix showing skipped transfers.
turn not an error to debug
bump file timeout
bump hashfs version
bump version number
bump version number in libsx
chown data directory too (bb #570)
update NEWS
3rdparty: update nginx to 1.6.1
cosmetics
set rebalance ttl to 7 days
Introduce progress output for fast cluster to cluster transfer (bb#709)

Change sxi_cluster_query function to be a wrapper of
sxi_cluster_query_track. Now xfer_stat structure is passed to struct
generic_ctx context to enable progress tracking for normal generic
transfers too. This is done if track_xfer parameter is set to positive
though.

Update sxcp tool to fit both direction transfers.