Made the WM_DESTROY fix official

The fix for #85, #93, #97 and #123 has been out and vetted by users for
quite a while now and so I'm making it the default behavior. Instead of
calling SetDestroyHandleBehavior(true) to enable it, it is now enabled
by default and can be disabled by calling
SetDestroyHandleBehavior(false).

src/ScintillaNET/Scintilla.cs

@@ -26,7 +26,7 @@ public class Scintilla : Control
         #region Fields
 
         // WM_DESTROY workaround
-        private static bool? reparentGlobal;
+        private static bool? reparentAll;
         private bool reparent;
 
         // Static module data
@@ -2261,14 +2261,17 @@ public unsafe void SetKeywords(int set, string keywords)
         /// <summary>
         /// Sets the application-wide behavior for destroying <see cref="Scintilla" /> controls.
         /// </summary>
-        /// <param name="reparent">true to reparent Scintilla controls to message-only windows when destroyed rather than actually destroying the control handle; otherwise, false.</param>
+        /// <param name="reparent">
+        /// true to reparent Scintilla controls to message-only windows when destroyed rather than actually destroying the control handle; otherwise, false.
+        /// The default is true.
+        /// </param>
         /// <remarks>This method must be called prior to the first <see cref="Scintilla" /> control being created.</remarks>
         public static void SetDestroyHandleBehavior(bool reparent)
         {
             // WM_DESTROY workaround
-            if (Scintilla.reparentGlobal == null)
+            if (Scintilla.reparentAll == null)
             {
-                Scintilla.reparentGlobal = reparent;
+                Scintilla.reparentAll = reparent;
             }
         }
 
@@ -6020,8 +6023,8 @@ public int Zoom
         public Scintilla()
         {
             // WM_DESTROY workaround
-            if (Scintilla.reparentGlobal.HasValue)
-                reparent = (bool)Scintilla.reparentGlobal;
+            if (Scintilla.reparentAll == null || (bool)Scintilla.reparentAll)
+                reparent = true;
 
             // We don't want .NET to use GetWindowText because we manage ('cache') our own text
             base.SetStyle(ControlStyles.CacheText, true);