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/generalsettings.cpp

@@ -62,7 +62,7 @@ QString GeneralSettings::id() const
     return QLatin1String("A.General");
 }
 
-QString GeneralSettings::trName() const
+QString GeneralSettings::displayName() const
 {
     return tr("General");
 }
@@ -72,7 +72,7 @@ QString GeneralSettings::category() const
     return QLatin1String(Core::Constants::SETTINGS_CATEGORY_CORE);
 }
 
-QString GeneralSettings::trCategory() const
+QString GeneralSettings::displayCategory() const
 {
     return QCoreApplication::translate("Core", Core::Constants::SETTINGS_TR_CATEGORY_CORE);
 }