TextEditor: Remove one stack of EditorWidget constructors

There are conceptually only two: one that operates a new document,
and one that shares one. Being explicit makes moving data over to
the Editor hierarchy easier. Convenience can be re-added there,
later.

Change-Id: I9b34ff26628c99ffff01201dcf99332d5e7253e9
Reviewed-by: Christian Stenger <christian.stenger@digia.com>
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/vcsbase/vcsbaseeditor.cpp

@@ -648,7 +648,7 @@ QComboBox *VcsBaseEditorWidgetPrivate::entriesComboBox()
 */
 
 VcsBaseEditorWidget::VcsBaseEditorWidget(const VcsBaseEditorParameters *type, QWidget *parent)
-  : BaseTextEditorWidget(parent),
+  : BaseTextEditorWidget(new TextEditor::BaseTextDocument, parent),
     d(new Internal::VcsBaseEditorWidgetPrivate(this, type))
 {
     viewport()->setMouseTracking(true);