-Made relationship lines appear based on theme settings, not previous hack
-Fix drawing of relationship lines (was broken)
-Fix double initialization of theme settings
OpenBSD does not support dual stacking, disabling IPv6 for now.
Will possibly come back if/when we get websocket running using our own
NetSocket class.
If it needs to be hardcoded (for the sake of reproducible builds),
it should be together with the other hardcoded version info.
And yeah, two months in, let's move to 2019.
Acknowledge mouse button events as position tellers (to make picking more solid; for instance, the touch mouse is raised with a mouse unpressed event that may have a more current position)
Forget mouse position for physics if touch mouse raised (because the position known as last is no longer meaningful)
Remove needless check for mouse over/exit (now there's code to inject an spurious move for cases where camera/objects have moved)
Restrict 2D mouse over/exit to mouse events (including emulated from touch; true touches shouldn't trigger the signals)
Fixes#26460.
