(In revision:878) Check added to ensure that when we get the ID of the last user to use the system, that the ID is still valid. If it isn't, then FALSE is returned instead.

Fixes* 103.

Updating tickets (#1, #21, #22, #44, #55, #70, #71, #82, #96, #102, #103, #104)

Updating tickets (#63, #65, #75, #84, #87, #89, #93, #185, #10, #57, #64, #69, #70, #74, #79, #80, #82, #83, #85, #86, #88, #90, #91, #96, #97, #98, #99, #100, #101, #104, #105, #109, #115, #116, #117, #120, #126, #128, #130, #131, #133, #135, #153, #163, #169, #171, #173, #179, #180, #181, #184, #187, #188, #194, #195, #198, #203, #205, #218, #220, #226, #231, #236, #239, #240, #242, #247, #252, #5, #6, #11, #20, #25, #26, #27, #29, #30, #38, #40, #42, #43, #44, #46, #49, #50, #51, #52, #53, #55, #58, #59, #60, #61, #71, #92, #102, #103, #106, #107, #108, #112, #113, #114, #118, #119, #121, #129, #137, #140, #141, #144, #145, #146, #147, #149, #150, #151, #152, #154, #156, #157, #158, #160, #161, #162, #165, #167, #168, #172, #176, #182, #183, #191, #192, #193, #196, #197, #204, #206, #210, #215, #217, #222, #228, #230, #232, #234, #235, #237, #243, #249, #1, #4, #9, #12, #13, #16, #62, #78, #164, #166, #189, #190, #199, #200, #208, #209, #211, #212, #19, #47, #48)