CCBC-258 explicitly check that the server initialized correctly

We must check return values from buffer allocator

Change-Id: Ibc4c6718c461b8c943c410270d2d6b03155c6e42
Reviewed-on: http://review.couchbase.org/28685
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>