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/projectexplorer/buildprogress.h

@@ -44,12 +44,13 @@ class BuildProgress : public QWidget
 {
     Q_OBJECT
 public:
-    BuildProgress(TaskWindow *taskWindow);
+    BuildProgress(TaskWindow *taskWindow, Qt::Orientation orientation = Qt::Vertical);
 
 private slots:
     void updateState();
 
 private:
+    QWidget *m_contentWidget;
     QLabel *m_errorIcon;
     QLabel *m_warningIcon;
     QLabel *m_errorLabel;