Check subsequent functionality in CCBC-275 test

Previously it was mistakenly assumed that the reason for not checking
the return code of operations which were to succeed was because of
issues in the Mock. in fact this is because the SASL context has not
actually been reset in lcb_failout_server

Change-Id: I0af4ae7e850c6f41c582d8f297d43ec188412527
Reviewed-on: http://review.couchbase.org/29690
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Add SASL related info to lcb_cntl

This creates a new version of MEMDNODE_INFO which returns the effective
SASL method, as well as a FORCE_SASL_MECH command which will fail the
server if it cannot utilize the user-defined auth method

Change-Id: I292218164cc5482ebb45e791f2c710b50a78b312
Reviewed-on: http://review.couchbase.org/29688
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tests for basic SASL mech handling

This uses LCB_CNTL_FORCE_SASL_MECH to verify that we can use a given
SASL method. This shall be extended in the future to check against
things like SASL_CRAM_MD5 and the like when the mock supports it

Change-Id: Ie0df3e78f5ae1fe2eb14591048cffe3dfc11db05
Reviewed-on: http://review.couchbase.org/29689
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>