TargetSetupPage: Generalize the page

Generalize the target setup page and move it into projectexplorer

Move the qmake specific code into a projectimporter class with
a specialization for qmake projects in the qt4projectmanager.

This change depends heavily on the BuildConfigurationFactory cleanups
done earlier and completes that change in such a way that generic
build configuration factories are now in theory possible. The
remaining problem is how to select the best factory of several that
claim to be able to handle a kit and that is left for the next patch.

Change-Id: I47134cb1938c52adebcdc1ddfe8dbf26abbbbeee
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/plugins/projectexplorer/buildconfiguration.cpp

@@ -341,6 +341,18 @@ IBuildConfigurationFactory *IBuildConfigurationFactory::find(Target *parent, con
     return 0;
 }
 
+// setup
+IBuildConfigurationFactory *IBuildConfigurationFactory::find(Kit *k, const QString &projectPath)
+{
+    QList<IBuildConfigurationFactory *> factories
+            = ExtensionSystem::PluginManager::instance()->getObjects<IBuildConfigurationFactory>();
+    foreach (IBuildConfigurationFactory *factory, factories) {
+        if (factory->canSetup(k, projectPath))
+            return factory;
+    }
+    return 0;
+}
+
 // create
 IBuildConfigurationFactory * IBuildConfigurationFactory::find(Target *parent)
 {