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/coreplugin/editmode.h

@@ -55,11 +55,11 @@ public:
     ~EditMode();
 
     // IMode
-    QString name() const;
+    QString displayName() const;
     QIcon icon() const;
     int priority() const;
     QWidget* widget();
-    const char* uniqueModeName() const;
+    QString id() const;
     QList<int> context() const;
 
 private slots: