Toolchain: Update target list on tool chain changes

Change-Id: I8f7109295449960c3a44db75e20e81b7733088b4
Reviewed-on: http://codereview.qt.nokia.com/730
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Christian Kandeler <christian.kandeler@nokia.com>

src/plugins/projectexplorer/target.cpp

@@ -550,6 +550,9 @@ bool Target::fromMap(const QVariantMap &map)
 
 ITargetFactory::ITargetFactory(QObject *parent) :
     QObject(parent)
-{ }
+{
+    connect(ToolChainManager::instance(), SIGNAL(toolChainsChanged()),
+            this, SIGNAL(supportedTargetIdsChanged()));
+}
 
 } // namespace ProjectExplorer