SERVER-11776 Replication 'isself' check should allow mapped ports

    'isself' should match the ports only if the hosts are being string matched.
    In cases where an instance is being addressed through a proxy port,
    port matching is an incorrect check - it invalidates a genuine match.

Signed-off-by: Benety Goh <benety@mongodb.com>
SERVER-11776 added scott's replication test for the isself command with mapped ports
SERVER-11776 move port check outside loop
SERVER-8492 SERVER-13893 Test for detecting named/unnamed unix socket

Signed-off-by: Benety Goh <benety@mongodb.com>
SERVER-13022 added option to set permissions on UNIX domain socket file

Signed-off-by: Benety Goh <benety@mongodb.com>
SERVER-13883 findAndModify return null if !new and doc not found

Fixes an edge case where findAndModify would return {} instead of null
if the doc was not found (specifically: if sort was specified and the
update resulted in an upsert).
SERVER-13883 findAndModify command should accept update:{}