Refs #4858 Add spectrum range options to interface.
Refs #4858 Add validation to interface options.
Refs #4858 Hook options up to python code.
Refs #4858 Add sequential fit option.
Refs #4858 Hook sequential fit option up to python script.
Refs #4858 Don't plot graph with single data point.
Merge branch 'feature/4858_msdfit_ui_upgrade' into develop