some OnAttributeChanged events would not be fired, added changed check for some attributes

Source/Basic Shapes/SvgCircle.cs

@@ -36,27 +36,43 @@ namespace Svg
             get { return this._centerX; }
             set
             {
-                this._centerX = value;
-                this.IsPathDirty = true;
+            	if(_centerX != value)
+            	{
+            		this._centerX = value;
+            		this.IsPathDirty = true;
+            		OnAttributeChanged(new AttributeEventArgs{ Attribute = "cx", Value = value });
+            	}
             }
         }
 
         [SvgAttribute("cy")]
         public virtual SvgUnit CenterY
         {
-            get { return this._centerY; }
-            set
-            {
-                this._centerY = value;
-                this.IsPathDirty = true;
-            }
+        	get { return this._centerY; }
+        	set
+        	{
+        		if(_centerY != value)
+        		{
+        			this._centerY = value;
+        			this.IsPathDirty = true;
+        			OnAttributeChanged(new AttributeEventArgs{ Attribute = "cy", Value = value });
+        		}
+        	}
         }
 
         [SvgAttribute("r")]
         public virtual SvgUnit Radius
         {
-            get { return this._radius; }
-            set { this._radius = value; this.IsPathDirty = true; }
+        	get { return this._radius; }
+        	set
+        	{
+        		if(_radius != value)
+        		{
+        			this._radius = value;
+        			this.IsPathDirty = true;
+        			OnAttributeChanged(new AttributeEventArgs{ Attribute = "r", Value = value });
+        		}
+        	}
         }
 
         /// <summary>

Source/Basic Shapes/SvgRectangle.cs

@@ -46,13 +46,16 @@ namespace Svg
         [SvgAttribute("x")]
         public SvgUnit X
         {
-            get { return _x; }
-            set
-            {
-                _x = value;
-                OnAttributeChanged(new AttributeEventArgs{ Attribute = "x", Value = value });
-                IsPathDirty = true;
-            }
+        	get { return _x; }
+        	set
+        	{
+        		if(_x != value)
+        		{
+        			_x = value;
+        			OnAttributeChanged(new AttributeEventArgs{ Attribute = "x", Value = value });
+        			IsPathDirty = true;
+        		}
+        	}
         }
 
         /// <summary>
@@ -61,13 +64,16 @@ namespace Svg
         [SvgAttribute("y")]
         public SvgUnit Y
         {
-            get { return _y; }
-            set
-            {
-                _y = value;
-                OnAttributeChanged(new AttributeEventArgs{ Attribute = "y", Value = value });
-                IsPathDirty = true;
-            }
+        	get { return _y; }
+        	set
+        	{
+        		if(_y != value)
+        		{
+        			_y = value;
+        			OnAttributeChanged(new AttributeEventArgs{ Attribute = "y", Value = value });
+        			IsPathDirty = true;
+        		}
+        	}
         }
 
         /// <summary>
@@ -76,13 +82,16 @@ namespace Svg
         [SvgAttribute("width")]
         public SvgUnit Width
         {
-            get { return _width; }
-            set
-            {
-                _width = value;
-                OnAttributeChanged(new AttributeEventArgs{ Attribute = "width", Value = value });
-                IsPathDirty = true;
-            }
+        	get { return _width; }
+        	set
+        	{
+        		if(_width != value)
+        		{
+        			_width = value;
+        			OnAttributeChanged(new AttributeEventArgs{ Attribute = "width", Value = value });
+        			IsPathDirty = true;
+        		}
+        	}
         }
 
         /// <summary>
@@ -91,13 +100,16 @@ namespace Svg
         [SvgAttribute("height")]
         public SvgUnit Height
         {
-            get { return _height; }
-            set
-            {
-                _height = value;
-                OnAttributeChanged(new AttributeEventArgs{ Attribute = "height", Value = value });
-                IsPathDirty = true;
-            }
+        	get { return _height; }
+        	set
+        	{
+        		if(_height != value)
+        		{
+        			_height = value;
+        			OnAttributeChanged(new AttributeEventArgs{ Attribute = "height", Value = value });
+        			IsPathDirty = true;
+        		}
+        	}
         }
 
         /// <summary>

Source/Paths/SvgPath.cs

@@ -18,7 +18,6 @@ namespace Svg
     public class SvgPath : SvgVisualElement
     {
         private GraphicsPath _path;
-        private int _pathLength;
 
         /// <summary>
         /// Gets or sets a <see cref="SvgPathSegmentList"/> of path data.
@@ -41,8 +40,8 @@ namespace Svg
         [SvgAttribute("pathLength")]
         public int PathLength
         {
-            get { return this._pathLength; }
-            set { this._pathLength = value; }
+        	get { return this.Attributes.GetAttribute<int>("pathLength"); }
+            set { this.Attributes["pathLength"] = value; }
         }
 
 		

Source/Text/SvgText.cs

@@ -85,13 +85,16 @@ namespace Svg
         [SvgAttribute("x")]
         public virtual SvgUnit X
         {
-            get { return this._x; }
-            set 
-            { 
-            	this._x = value; 
-            	this.IsPathDirty = true;
-            	OnAttributeChanged(new AttributeEventArgs{ Attribute = "x", Value = value });
-            }
+        	get { return this._x; }
+        	set
+        	{
+        		if(_x != value)
+        		{
+        			this._x = value;
+        			this.IsPathDirty = true;
+        			OnAttributeChanged(new AttributeEventArgs{ Attribute = "x", Value = value });
+        		}
+        	}
         }
 
         /// <summary>
@@ -101,13 +104,16 @@ namespace Svg
         [SvgAttribute("y")]
         public virtual SvgUnit Y
         {
-            get { return this._y; }
-            set 
-            { 
-            	this._y = value; 
-            	this.IsPathDirty = true; 
-            	OnAttributeChanged(new AttributeEventArgs{ Attribute = "y", Value = value });
-            }
+        	get { return this._y; }
+        	set
+        	{
+        		if(_y != value)
+        		{
+        			this._y = value;
+        			this.IsPathDirty = true;
+        			OnAttributeChanged(new AttributeEventArgs{ Attribute = "y", Value = value });
+        		}
+        	}
         }
 
         /// <summary>