fix docking issues

- editor cant be disassociated from the menu
- a fix exists for the 3rd part component, but will be only applied if it's accepted by the people in charge (to consider when building CE from source).
- the fix will be applied in the next CE binary release (even if not  officially cherry merged to the Lazarus components).

fix #13
fix #4

waiting for that a widget must not undocked (right click) before getting closed.

src/ce_editor.lfm

@@ -6,6 +6,7 @@ inherited CEEditorWidget: TCEEditorWidget
   Caption = 'Source editor'
   ClientHeight = 406
   ClientWidth = 465
+  OnCloseQuery = FormCloseQuery
   inherited Back: TPanel
     Height = 406
     Width = 465

src/ce_editor.pas

@@ -34,6 +34,7 @@ type
     macRecorder: TSynMacroRecorder;
     editorStatus: TStatusBar;
     mnuEditor: TPopupMenu;
+    procedure FormCloseQuery(Sender: TObject; var CanClose: boolean);
     procedure mnuedCopyClick(Sender: TObject);
     procedure mnuedCutClick(Sender: TObject);
     procedure mnuEditorPopup(Sender: TObject);
@@ -139,6 +140,13 @@ begin
   fErrList.Free;
   inherited;
 end;
+
+procedure TCEEditorWidget.FormCloseQuery(Sender: TObject; var CanClose: boolean);
+begin
+  // grants the window not to be undocked.
+  // additional fix, depend on of http://bugs.freepascal.org/view.php?id=28325
+  CanClose := Parent = nil;
+end;
 {$ENDREGION}
 
 {$REGION ICEMultiDocObserver ---------------------------------------------------}