Paint style

[what-the-diff[bot]]

• Changed JMColor to PaintStyle
• Added alpha setter in PaintStyle class
• Modified FirstDrawThenFillAnimation and PointInterpolationCanonical classes accordingly
• In JavaFXRenderer.java, the drawColor and fillColor are changed to use getFXPaint instead of getFXColor
• In ConfigLoader.java, setDrawcolor is used instead of copyFrom for both draw color and fill color
• A new class GradientStop was added in order to hold a bunch of colors that define a linear or radial gradient
• The class JMColor has been modified to implement the interface PaintStyle.
• A new method getFXPaint() was added, which returns a javafx paint object with this color and alpha value (if any).
• New methods setAlpha(double) and getAlpha() were added in order to be able to change or read the alpha component of this color from outside classes that use it as a style for their shapes/objects.
• Method interpolate(JMColor p, double t) was renamed into interpolate(PaintStyle p, double t), since now we can also interpolate between different types of styles: colors or gradients (linear or radial). This is done by checking if parameter "p" is an instanceof JMColor; otherwise we check if it's an instanceof JMLinearGradient o JMRadialGradient instead; finally returning itself ("this") when none of these conditions are met because I don't know what else could happen here... :D . In case "p" IS indeed another type of gradient than linear one (JMRadialGradient), then its own implementation will take care about how exactly should they be mixed together! :)
• Added a new interface PaintStyle
• Changed the type of drawColor and fillColor from JMColor to PaintStyle in Stylable interface
• Modified MODrawPropertiesArray class accordingly (setDraw/FillAlpha, setDraw/FillColors)
• Created JMLinearGradient and JMRadialGradient classes implementing the new interface PaintStyle
• In ColorScale.java, the method getColorValue() was changed to use interpolate instead of getInterpolatedColor
• In MathObject.java, drawcolor and fill color were changed from JMColors to PaintStyles
• MultiShapeObject's methods for setting colors were also updated in a similar way as above (JMColors -> PaintStyle)
• SVGMathObject had some changes made that are related to how it handles parsing SVG files: