Orbits with close perihelions are not displayed correctly

[Bogdan Marinov]

The orbits of solar system bodies that have high eccentricity and a perihelion close to the Sun are not displayed correctly (see the attached screenshots).

The displayed orbit for C/2006 P1 (McNaught) is the one defined in the default ssystem.ini with the "orbit_visualization_period" parameter set to 10000.

The displayed orbit for 2P/Encke is defined with the following:

[2PEncke]
albedo = 0.443659680267592
color = 1.0, 1.0, 1.0
coord_func = comet_orbit
lighting = false
name = 2P/Encke
orbit_ArgOfPericenter = 186.5242
orbit_AscendingNode = 334.5718
orbit_Eccentricity = 0.848265
orbit_Inclination = 11.7843
orbit_PericenterDistance = 0.336152
orbit_TimeAtPericenter = 2455415.01019676
orbit_visualization_period = 1204
parent = Sun
radius = 5
tex_map = nomap.png

[Alexander Wolf (alexwolf)]

I'm increased a numbers of orbit segments for calculation of positions for SSO's and now comets orbit more smooth, without angles like on screenshots. Now comets orbit displayed more correct, include parts near close perihelions.

Diff: http://bazaar.launchpad.net/~stellarium/stellarium/trunk/revision/5328