SERVER-14580 added tests for $natural

Closes #714

Signed-off-by: Benety Goh <benety@mongodb.com>
SERVER-14652 update tests for localhost exception

Closes #721

Signed-off-by: Benety Goh <benety@mongodb.com>
Revert "SERVER-14580 added tests for $natural"
Merge remote-tracking branch 'upstream/master'