Natural slopes – 1.2

Version 1.2 brings a few more extensions.

• Colored nodes can have their slopes. But the full palette cannot be applied as colorfacedir nodes can have only 8 colors instead of 256.
• All change types (stomp, dig/place, time, map generation) have their global factor defined in settingstype, not just only on generation.
• Tired of managing dependencies? Just call naturalslopeslib.propagate_overrides() somewhere in your code and any modification applied to a node after the slopes are defined will be propagated to the slopes too (not applied by default for backward compatibility). You then just need to add the dependency for the original node definition and what happens after is no longer a problem.
• And a few bugfixes, not a big deal...