Blender Git Loki

Revert "Experimental Tweak: Only show relationship lines between objects when either the parent/child object is selected"

This reverts commit 912931964723cb69dafd4adebe3daf093e3e78c1.

This meant users needed to select everything to see relationship lines,
this isn't always easy since objects can have limit-selection set.

This could be made into an enum option if it's important.