FormulaBar and StatusBar added, code rearranged

Code rearranged in GraphicalInterface to group similar items together.
More comments including group titles added. Added fileList item selected
when FBA run. Tab selection code added for some menu actions. Also when
opt file in fileList selected, Reaction tab automatically selected.
Merge pull request #8 from jimkell/master

FormulaBar and StatusBar added, code rearranged