don't print URL when there is a network error
sxvol: fix filter version check
fix sxcat of multiple files (bb #856)
handle hdist change failure
handle failure of "infallible" jobs
nss: drop unused file open
fix file leak
libsx/client: check more close() after write (bb#476)
more close() checks (bb#476)
sxi_hashop_proto_decuse_hash for unbump
log a message and don't run GC if we detect a serious problem
bb #386

Don't hardcode settings can be locally tweaked for performance.
Values that should be synchronized cluster-wide or
that are used with STRIFY in queries are still hardcoded (bb #335).
wrap gc_periodic in small transcations

avoid warnings about database locked
Check if sqlite really deleted a row using sqlite3_changes()

Update volume size using only one query which doesn't require locking
h->db
Push volume size changes instead of pulling on volumes listing
Cosmetics:

Remove some spam, do not reset h->is_rebalancing and fix spurious whitespaces