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/cvs/cvscontrol.h

@@ -43,7 +43,7 @@ class CVSControl : public Core::IVersionControl
     Q_OBJECT
 public:
     explicit CVSControl(CVSPlugin *plugin);
-    virtual QString name() const;
+    virtual QString displayName() const;
 
     virtual bool managesDirectory(const QString &directory) const;
     virtual QString findTopLevelForDirectory(const QString &directory) const;