Additionally, CI builds were failing due to the commit where SpineSkin
had an init() method added, but this caused Godot 3.x builds to fail.
Our formatter was also run, so it should no longer fail the format
check.
Addresses the loader/saver registration issue in #2899.
Additionally, makes it such that you can adjust the SpineSkeletonData in
the inspector without crashes. This appears to have been caused by a
dangling pointer.
Finally, double-clicking on JSON in the inspector opens the text editor
and does not crash the Godot editor.
