Revision of MG and MIS

[samm82]

As stated in #81, "We should look at the design of GlassBR. The MG and MIS are in need of revision. The design should actually be quite simple; based on the code implementation, it seems more confusing than it should be. The syntax of the functions in the new design may include Exceptions that we don't currently have, but we should start with the design for determining the exceptions, rather than the code."

[smiths]

I'm still working on this.

[niazim3]

Just noting that MIS for GlassBR is being looked at in #105.