-Add root motion support in AnimationTree.

-Add RootMotionView, to debug root motion in 3D (disabled in runtime)

editor/plugins/root_motion_editor_plugin.h

@@ -0,0 +1,42 @@
+#ifndef ROOT_MOTION_EDITOR_PLUGIN_H
+#define ROOT_MOTION_EDITOR_PLUGIN_H
+
+#include "editor/editor_inspector.h"
+#include "editor/editor_spin_slider.h"
+#include "editor/property_selector.h"
+#include "scene/animation/animation_tree.h"
+
+class EditorPropertyRootMotion : public EditorProperty {
+	GDCLASS(EditorPropertyRootMotion, EditorProperty)
+	Button *assign;
+	Button *clear;
+	NodePath base_hint;
+
+	ConfirmationDialog *filter_dialog;
+	Tree *filters;
+
+	void _confirmed();
+	void _node_assign();
+	void _node_clear();
+
+protected:
+	static void _bind_methods();
+	void _notification(int p_what);
+
+public:
+	virtual void update_property();
+	void setup(const NodePath &p_base_hint);
+	EditorPropertyRootMotion();
+};
+
+class EditorInspectorRootMotionPlugin : public EditorInspectorPlugin {
+	GDCLASS(EditorInspectorRootMotionPlugin, EditorInspectorPlugin)
+
+public:
+	virtual bool can_handle(Object *p_object);
+	virtual void parse_begin(Object *p_object);
+	virtual bool parse_property(Object *p_object, Variant::Type p_type, const String &p_path, PropertyHint p_hint, const String &p_hint_text, int p_usage);
+	virtual void parse_end();
+};
+
+#endif // ROOT_MOTION_EDITOR_PLUGIN_H