Celestia should be case-sensitive

[SevenSpheres]

Celestia is currently case-insensitive, which can cause problems. For example, there are stars called both A Cen and a Cen (note that I'm not talking about ALF Cen), but either string always selects a Cen. This causes worse problems when trying to define a multiple star system with both an "AB" barycenter and an "Ab" component. The search box should remain case-insensitive though, so the user doesn't have to capitalize search terms.

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How it is now: typing a cen returns A Cen; selecting it selects a Cen. How it should be: typing a cen returns both A Cen and a Cen; selecting them works as expected.