Show build and search progress detail also in status bar.

A widget specifically layouted for the status bar can now be registered
with the progress information. The newest one is made visible next to
the summary progress bar. If a newer one vanishes, the older becomes
visible again.

Change-Id: Iedf0e88a542ea442ae86fa51c792c68fbc6eef3c
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/coreplugin/progressmanager/futureprogress.h

@@ -71,6 +71,9 @@ public:
     void setWidget(QWidget *widget);
     QWidget *widget() const;
 
+    void setStatusBarWidget(QWidget *widget);
+    QWidget *statusBarWidget() const;
+
     bool isFading() const;
 
     QSize sizeHint() const;
@@ -83,6 +86,8 @@ signals:
     void hasErrorChanged();
     void fadeStarted();
 
+    void statusBarWidgetChanged();
+
 protected:
     void mousePressEvent(QMouseEvent *event);
     void paintEvent(QPaintEvent *);