- In the fit tab, when I hit enter in a parameter box, it should update. 
	Right now the only way to update is to click somewhere else.
- When fitting data with a model, the plotted model should have a proper name, not "Fitness"
- The constrained fit button should have a normal, fixed, size.
- The close tab button should be inside the tab it closes, like the fit button.
- If I load data, select if for fitting, then close the fit tab, I can't re-select it 
	for fitting if all other fit tabs are closed and I'm looking at the simultaneous fitting tab. 
- Chi squared should be updated when model parameters are changed.
- The parameters resulting from contraints should be updated on the fit panel.