Add names for comets, asteroids, artsats

[Bill-Gray]

Ideally, if one loads observations of C/2007 Q3, Find_Orb would show it as "C/2007 Q3 (Siding Spring)". If you loaded observations of the minor planet (4179), it would show up as "(4179) Toutatis". And the artsat 1999-066A would appear as 1999-066A = NORAD 25989 = XMM-Newton. Files with these cross-designations are available; it wouldn't be difficult for Find_Orb to use them.