Add Preference of Midpoint Orb Color [0.81b]

Added a new preference on the Utility->Preferences->Charts tab. At the bottom in the "Midpoint Sort Report" section added a new popup where you can choose which color to use for highlighting midpoints within orb. The colors are: "lavender, peachpuff, lightyellow, lightblue, palegreen, paleturquoise, seashell, whitesmoke, yellow.