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/cmakeprojectmanager/cmakeprojectmanager.cpp

@@ -244,7 +244,7 @@ QString CMakeSettingsPage::id() const
     return QLatin1String("CMake");
 }
 
-QString CMakeSettingsPage::trName() const
+QString CMakeSettingsPage::displayName() const
 {
     return tr("CMake");
 }
@@ -254,7 +254,7 @@ QString CMakeSettingsPage::category() const
     return QLatin1String("M.CMake");
 }
 
-QString CMakeSettingsPage::trCategory() const
+QString CMakeSettingsPage::displayCategory() const
 {
     return tr("CMake");
 }