This is just a cleanup work to hide some of the private state of
ReplSetTest so it is easier to encapsulate and add new logic. Also enables
strict mode.
New testing certificates generated for MongoDB using x509gen. Test were also updated slightly to accommodate for new subject alternative names and such.
All instances of "sslAllowInvalidCertificates" were removed from src/mongo/shell.
Closes#724
Signed-off-by: Benety Goh <benety@mongodb.com>