Improved mask also work on erase. Improved shaders for layer opacity, now when drawing doesn't change opacity. Improved layers panel layout to be similar to PS. Added layer blending option and visibility. Added custom icons to checkboxes and fixed the combobox items.

src/node_image.h

@@ -24,4 +24,5 @@ public:
     virtual void restore_context() override;
     virtual void parse_attributes(kAttribute ka, const tinyxml2::XMLAttribute* attr) override;
     virtual void draw() override;
+    bool set_image(const std::string& path);
 };