MB-8662: pass purge timestamp to couch compactor

Change-Id: I0936e91911417cb6018fac42e58beaaeac383aad
Reviewed-on: http://review.couchbase.org/27792
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-8662: added REST API for setting purge interval

Change-Id: I787817e45e9c0550cc46fbaebd422d76a92f3da4
Reviewed-on: http://review.couchbase.org/27793
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-4786: use sigar memory stats for UI server memory usage gauge

We're now sending mem_total and mem_free with heartbeats and node info
now prefers them to erlang's memory info metrics.

Change-Id: Iaa7cb7d868da54043871f4de5ad78beaae62000d
Reviewed-on: http://review.couchbase.org/27859
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-8662: implemented ui for purge interval setting

Change-Id: I6f114cf67e86613b236d89f4bf943e4c1e6d6036
Reviewed-on: http://review.couchbase.org/27794
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-100: don't crash compaction_daemon on unknown config field

Which complicates adding new compaction setting fields

Change-Id: Ie12267eefac91b5dbf82f7ee74317fdbc7e5fe60
Reviewed-on: http://review.couchbase.org/27858
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Merge remote-tracking branch 'couchbase/2.2.0'

* couchbase/2.2.0:
  MB-100: don't crash compaction_daemon on unknown config field
  MB-8662: implemented ui for purge interval setting
  MB-4786: use sigar memory stats for UI server memory usage gauge
  MB-8662: added REST API for setting purge interval
  MB-8662: pass purge timestamp to couch compactor

Change-Id: Ide6d9a63b75d92fb7f1e43d3e56f4a65aa0e9438