JCBC-567: Remember initial bootstrap method

Motivation
----------

In some situations like recovering connection after network outage, the
client might stop using Carrier Publication protocol to receive cluster
configuration.

Modifications
-------------

BucketConfigurationProvider.isBinary property refactored from simple
boolean to type with three values to clearly describe the bootstrap
protol or state that the bootstrap process have not decided on any of
them.

Result
------

When someone signals that configuration has been
outdated (BucketConfigurationProvider.signalOutdated), the last method
will be tried first, and then (if it was CCCP) the library will try to
bootstrap from HTTP

Change-Id: I6218ea6ceba7acddfcb4b43d81cc83a3cb6bbf6d
Reviewed-on: http://review.couchbase.org/41734
Reviewed-by: Matt Ingenthron <matt@couchbase.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>