bp: MB-12099 Handle unicode:characters_to_binary errors.
bp: MB-12099 Handle unicode:characters_to_binary errors.

Change-Id: Id2110b83b28cbcb23a00426e292e234663d0d38f
Orig-Reviewed-on: http://review.couchbase.org/41096
Reviewed-on: http://review.couchbase.org/42984
Reviewed-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>

nimishzynga/ns_server,ceejatec/ns_server,mschoch/ns_server,nimishzynga/ns_server,mschoch/ns_server,membase/ns_server,ceejatec/ns_server,ceejatec/ns_server,mschoch/ns_server,membase/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,ceejatec/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,mschoch/ns_server,membase/ns_server,mschoch/ns_server,ceejatec/ns_server,ceejatec/ns_server,membase/ns_server,membase/ns_server,mschoch/ns_server,membase/ns_server