CCBC-278: Use common config retry mechanism for bad configcache

- This uses the same error handling mechanism as when
  a bad configuration has been received from the network

- New LCB_CONFIG_CACHE_INVALID error code to notify the user of such a
  situation

Change-Id: Iecda5d4b2d4650613046ac82f6587fa8b65bedfb
Reviewed-on: http://review.couchbase.org/29454
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>