MB-7720: deferred creation of the sample and default buckets

.. to the very end of Create Cluster wizard
eliminated flicker on default buckets page
replaced "loading buckets" dialog with a spinner
removed "Installed Samples" section from the sample buckets page
removed setupDefaultBucket REST API

Change-Id: I561ac0d76bc220be682ea55a97f699b410c85dc7
[alk@tut.by: fixed minor formatting issue]
Signed-off-by: Aliaksey Kandratsenka <alk@tut.by>
Reviewed-on: http://review.couchbase.org/27314
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
MB-100: undo addition of sleep into menelaus_web

That was only done for testing and somehow I failed to remove it
before amending previous change.

Change-Id: Ica192c41bc97c5d5848b0f38225f49b938b60f1d
Reviewed-on: http://review.couchbase.org/27384
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Artem Stemkovski <artem@couchbase.com>
Reviewed-by: Artem Stemkovski <artem@couchbase.com>
separation of js/css: prefix 'js_' for sections

Change-Id: I3552df8716071c7810f1e253a48ade28ce702479
Reviewed-on: http://review.couchbase.org/27378
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
separation of js/css: prefixes for 'block-expander' functionality

Change-Id: I3569ef24efc2bb3cc52a4a4f744d2fdc39931528
Reviewed-on: http://review.couchbase.org/27379
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
separation of js/css: prefixes for analytics.js

Change-Id: I1b7bea466e0ce6930b291b636e1b4ab7158cb26e
Reviewed-on: http://review.couchbase.org/27380
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
separation of js/css: prefix 'dynamic_' for class 'disabled'

Change-Id: Ic77ae678784ed96468c9407394ada806e117d3c2
Reviewed-on: http://review.couchbase.org/27381
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>