Changed everything related to brushes/gradients to be correctly bindable

RGB.NET.Brushes/Gradients/AbstractGradient.cs

@@ -2,7 +2,7 @@
 // ReSharper disable MemberCanBePrivate.Global
 // ReSharper disable AutoPropertyCanBeMadeGetOnly.Global
 
-using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Linq;
 using RGB.NET.Core;
 
@@ -20,14 +20,19 @@ namespace RGB.NET.Brushes.Gradients
         /// <summary>
         /// Gets a list of the stops used by this <see cref="AbstractGradient"/>.
         /// </summary>
-        public IList<GradientStop> GradientStops { get; } = new List<GradientStop>();
+        public ObservableCollection<GradientStop> GradientStops { get; } = new ObservableCollection<GradientStop>();
 
+        private bool _wrapGradient;
         /// <summary>
         /// Gets or sets if the Gradient wraps around if there isn't a second stop to take.
         /// Example: There is a stop at offset 0.0, 0.5 and 0.75. 
         /// Without wrapping offset 1.0 will be calculated the same as 0.75; with wrapping it would be the same as 0.0.
         /// </summary>
-        public bool WrapGradient { get; set; }
+        public bool WrapGradient
+        {
+            get => _wrapGradient;
+            set => SetProperty(ref _wrapGradient, value);
+        }
 
         #endregion
 

RGB.NET.Brushes/Gradients/GradientStop.cs

@@ -8,19 +8,29 @@ namespace RGB.NET.Brushes.Gradients
     /// <summary>
     /// Represents a stop on a gradient.
     /// </summary>
-    public class GradientStop
+    public class GradientStop : AbstractBindable
     {
         #region Properties & Fields
 
+        private double _offset;
         /// <summary>
         /// Gets or sets the percentage offset to place this <see cref="GradientStop"/>. This should be inside the range of [0..1] but it's not necessary.
         /// </summary>
-        public double Offset { get; set; }
+        public double Offset
+        {
+            get => _offset;
+            set => SetProperty(ref _offset, value);
+        }
 
+        private Color _color;
         /// <summary>
         /// Gets or sets the <see cref="Color"/> of this <see cref="GradientStop"/>.
         /// </summary>
-        public Color Color { get; set; }
+        public Color Color
+        {
+            get => _color;
+            set => SetProperty(ref _color, value);
+        }
 
         #endregion
 

RGB.NET.Brushes/Gradients/RainbowGradient.cs

@@ -15,15 +15,25 @@ namespace RGB.NET.Brushes.Gradients
     {
         #region Properties & Fields
 
+        private double _startHue;
         /// <summary>
         /// Gets or sets the hue (in degrees) to start from.
         /// </summary>
-        public double StartHue { get; set; }
+        public double StartHue
+        {
+            get => _startHue;
+            set => SetProperty(ref _startHue, value);
+        }
 
+        private double _endHue;
         /// <summary>
         /// Gets or sets the hue (in degrees) to end the with.
         /// </summary>
-        public double EndHue { get; set; }
+        public double EndHue
+        {
+            get => _endHue;
+            set => SetProperty(ref _endHue, value);
+        }
 
         #endregion