MB-8120 Allow omitting ramQuotaMB when updating bucket settings.

Change-Id: Ib5fedd1cdef6ba6bb02fd13dcadb280a1bbe92d5
Reviewed-on: http://review.couchbase.org/30080
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
MB-100: removed unneeded logging for terse streaming bucket details

Change-Id: Id9ebf62ef238a93bf7fb43eb9373686f0d421179
Reviewed-on: http://review.couchbase.org/30103
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
MB-9460: dont crash rebalance in older compat modes

Recent code change blindly assumed that server groups is always going
to be present. But this is not the case as we're only creating that
config key as part of upgrading compat mode to 2.5 (i.e. when all
nodes are 2.5+). So in order to support mixed-version rebalance with
older versions we have to anticipate lack of this key

Change-Id: Ibe8c34f1e147668c818b267678c5709311f3ee72
Reviewed-on: http://review.couchbase.org/30104
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Merge branch 'for-rackaware'

* for-rackaware:
  MB-9460: dont crash rebalance in older compat modes
  MB-100: removed unneeded logging for terse streaming bucket details
  MB-8120 Allow omitting ramQuotaMB when updating bucket settings.

trivial merge

Change-Id: If6c42ab359584f3e9a9a2771d4dc0e50b72c112e