sqliterepo: fix TO-HONEYCOMB-586 (big sqliterepo bases)

Base transfers are now chunked (8MiB) by default.
Monolitic transfers are still supported.

Some return codes have been replaced by constants.

Change-Id: Iecc45841bdd333f5d45bd101c68255c8c14d9111
client: fix meta1 timeouts and a memory leak

Change-Id: I1b3e069bfca183b186b42a36002f71a8f2f9f558
(cherry picked from commit 56fa88b8e8da97418d2022b201d177eb48fc023f)
Several fixes and improvements

JSON fixed for service_info.
Finer decache in resolver.
m2v2_remote_touch_content fixed.
m2v2 does not generates events when disabled.

Change-Id: Ib145ba973ad7d9f3810c4c0fa4f30f1be1ff4639
zk-bootstrap doesn't fail on an error on the root node.

Change-Id: I8dfcb3622bc96f0af2356f96ba64f6edce99c065
Finer gauges for active threads, reliable accesslog delays

This patch provides the maximum number of active threads, and a round-robin storage for that information.
The granularity proposed is intervals of 1s over the past 30s, and intervals of 1 minute over the past 1 hour.
This data is used by the core server library to expose statistics, e.g.

	server.thread.max.1 = 0
	server.thread.max.5 = 1
	server.thread.max.15 = 2
	server.thread.max.30 = 2
	server.thread.max.60 = 3
	server.thread.max.300 = 3
	server.thread.max.900 = 3
	server.thread.max.3600 = 3

This patch also alters the accesslog format for gridd transports, and it is now unified with http transport.
An access log record now provides 2 treatment durations:
- the total time spent since the reception of the last buffer that completes the request
- the total treatment time, from the moment where a worker thread starts the request handling til the moment an answer is generated.
The delta between both delays is the time spent in the internals queues of the process.

The patch divides in:
- server/stats_holder.* :
  - drops the adherence to system time, the current timestamp is now received from the caller. This is necessary to manager counter with a granularity different than 1s.
  - New calls to compute the cumulative maximum
  - code simplification
- server/network_server.* :
  - new round-robin stats now managed
  - new stats exposed.
  - precise monotonic clock used on the last input
- server/transport_http.c :
  - useless variables removed.
  - accesslog format reviewed (timers printed : total time spent, time spent in queue)
- server/transport_gridd.c :
  - accesslog format reviewed (timers printed : total time spent, time spent in queue)
- sqlx/sqlx_service.c :
  - code adapted to match the lost "time adherence"

Change-Id: I248ae7a1937860e4062290e95b68465d7ec62821