#3 Add advanced support for selecting problems

Currently, only single Environment/init-file pairs can be
selected in the GUI, and all applicable Individual methods are
used. Work was started on an Advanced dialog (located in
the AdvancedOptions/AdvancedForm.cs file in the EngineGUI
project). However, due to the complicated nature of this
dialog, it was not completed for the initial release. The
dialog needs to be redesigned before it is used.