Add comparison operator to Color.
Dirty the Line3D and refresh it only if the data has actually been changed.
Merge pull request #3190 from fluffyfreak/fix-Line3D

Fix the Line3D rendering issue
Update Changelog.txt
Fix the construction of the Circle drawables. Two of the constructors were non-functional and only used in one place.
Merge pull request #3192 from fluffyfreak/fix-3191

Fix the construction of the Circle drawables.
Update Changelog.txt
Move StarSystem slave cache from Galaxy to Space.
FillCache callback was not called when all objects already existed before.
Debug output.
Factions code no longer uses global Galaxy object.
CustomSystems code no longer uses global Galaxy object.
Galaxy generator and caches no longer use global Galaxy object.
Fix Galaxy object searching itself via Pi::GetGalaxy().
Space no longer uses global Galaxy object.
Merge two constructors of Game to avoid another Pi:GetGalaxy reference.
Pass galaxy to StarSystem::Unserialize.
Give Game a m_galaxy member.
GalacticView, SectorView, SystemView, SystemInfoView and WorldView no longer use global Galaxy object.
Polit no longer accesses global Galaxy.