Implemented Find-Replace Overlay.

In response to issue eclipse-platform#1090. Goals for this overlay are a simple
and modern UI/UX for finding/replacing in eclipse.

Author: Maximilian Wittmer

bundles/org.eclipse.ui.workbench.texteditor/META-INF/MANIFEST.MF

@@ -9,6 +9,8 @@ Bundle-Vendor: %providerName
 Bundle-Localization: plugin
 Export-Package: 
  org.eclipse.ui.contentassist,
+ org.eclipse.ui.internal.findandreplace;x-friends:="org.eclipse.ui.workbench.texteditor.tests",
+ org.eclipse.ui.internal.findandreplace.status;x-friends:="org.eclipse.ui.workbench.texteditor.tests",
  org.eclipse.ui.internal.texteditor;texteditor=split;mandatory:=texteditor;x-friends:="org.eclipse.ui.editors",
  org.eclipse.ui.internal.texteditor.codemining;x-internal:=true,
  org.eclipse.ui.internal.texteditor.quickdiff;x-internal:=true,