Moving TabFolderLayout into SWT to have a single copy.

Fixes eclipse-platform/eclipse.platform.swt#1317

Author: deepika-u

ui/org.eclipse.pde.ui/META-INF/MANIFEST.MF

@@ -81,7 +81,7 @@ Require-Bundle:
  org.eclipse.ui.views;bundle-version="[3.12.100,4.0.0)",
  org.eclipse.jface.text;bundle-version="[3.24.200,4.0.0)",
  org.eclipse.ui.workbench.texteditor;bundle-version="[3.17.200,4.0.0)",
- org.eclipse.ui.editors;bundle-version="[3.17.100,4.0.0)",
+ org.eclipse.ui.editors;bundle-version="[3.19.0,4.0.0)",
  org.eclipse.debug.ui;bundle-version="[3.18.200,4.0.0)",
  org.eclipse.jdt.core;bundle-version="[3.36.0,4.0.0)",
  org.eclipse.jdt.debug.ui;bundle-version="[3.13.200,4.0.0)",

ui/org.eclipse.pde.ui/src/org/eclipse/pde/internal/ui/preferences/EditorPreferencePage.java

@@ -25,6 +25,7 @@
 import org.eclipse.pde.internal.ui.editor.text.ColorManager;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.layout.GridData;
+import org.eclipse.swt.layout.TabFolderLayout;
 import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;