Various improvements for BinEditor.

- Saving to file only takes modified data into account.
- Search functionality does not exhaust memory anymore.
- Searches can be canceled. This required updating the IFindSupport
  interface and all classes implementing it. No functional changes
  were done in those.

Reviewed-by: mae

src/plugins/coreplugin/editormanager/ieditor.h

@@ -40,6 +40,7 @@ class CORE_EXPORT IEditor : public IContext
 {
     Q_OBJECT
 public:
+
     IEditor(QObject *parent = 0) : IContext(parent) {}
     virtual ~IEditor() {}