Make method naming more consistent.

* Use id() for methods returning a string used to represent
    some type of object.
  * Use displayName() for strings that are meant to be user
    visible.
  * Quieten some warnings while touching the files anyway.
  * Move Factories to their products in the plugins where that
    was not done before.

Reviewed-by: dt

src/plugins/qt4projectmanager/qt4projectmanagerplugin.cpp

@@ -166,7 +166,7 @@ bool Qt4ProjectManagerPlugin::initialize(const QStringList &arguments, QString *
 
     //register actions
     m_projectContext = core->uniqueIDManager()->
-        uniqueIdentifier(Qt4ProjectManager::Constants::PROJECT_KIND);
+        uniqueIdentifier(Qt4ProjectManager::Constants::PROJECT_ID);
     QList<int> context = QList<int>() << m_projectContext;
     Core::Command *command;