minor notes in comments of Matrix classes

Source/OpenTK/Math/Matrix3.cs

@@ -101,7 +101,7 @@ namespace OpenTK
         }
 
         /// <summary>
-        /// Constructs a new instnace.
+        /// Constructs a new instance.
         /// </summary>
         /// <param name="matrix">A Matrix4 to take the upper-left 3x3 from.</param>
         public Matrix3(Matrix4 matrix)

Source/OpenTK/Math/Matrix4x3.cs

@@ -587,6 +587,7 @@ namespace OpenTK
         #region Multiply Functions
 
         /// <summary>
+        /// This isn't quite a multiply, but the result may be useful in some situations.
         /// Multiplies two instances.
         /// </summary>
         /// <param name="left">The left operand of the multiplication.</param>
@@ -600,6 +601,7 @@ namespace OpenTK
         }
 
         /// <summary>
+        /// This isn't quite a multiply, but the result may be useful in some situations.
         /// Multiplies two instances.
         /// </summary>
         /// <param name="left">The left operand of the multiplication.</param>
@@ -641,6 +643,7 @@ namespace OpenTK
         }
 
         /// <summary>
+        /// This isn't quite a multiply, but the result may be useful in some situations.
         /// Multiplies two instances.
         /// </summary>
         /// <param name="left">The left operand of the multiplication.</param>

Source/OpenTK/Math/Matrix4x3d.cs

@@ -584,6 +584,7 @@ namespace OpenTK
         #region Multiply Functions
 
         /// <summary>
+        /// This isn't quite a multiply, but the result may be useful in some situations.
         /// Multiplies two instances.
         /// </summary>
         /// <param name="left">The left operand of the multiplication.</param>
@@ -597,6 +598,7 @@ namespace OpenTK
         }
 
         /// <summary>
+        /// This isn't quite a multiply, but the result may be useful in some situations.
         /// Multiplies two instances.
         /// </summary>
         /// <param name="left">The left operand of the multiplication.</param>