Automatically configure examples opened from the welcome page.

Each example can now provide a list of platforms by the examples manifest
.xml file. This list can control the target configuration of the example
when it is opened in the welcomepage.

Change-Id: I893230fd2850b7a1272db71a7f589044d52041d1
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/projectexplorer/project.cpp

@@ -388,4 +388,9 @@ bool Project::needsConfiguration() const
     return false;
 }
 
+void Project::configureAsExampleProject(const QStringList &platforms)
+{
+
+}
+
 } // namespace ProjectExplorer