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/dialogs/ioptionspage.cpp

@@ -37,9 +37,9 @@
   Guidelines for implementing:
   \list
   \o id() is an id used for filtering when calling ICore:: showOptionsDialog()
-  \o trName() is the (translated) name for display.
+  \o displayName() is the (translated) name for display.
   \o category() is the category used for filtering when calling ICore:: showOptionsDialog()
-  \o trCategory() is the translated category
+  \o displayCategory() is the translated category
   \o apply() is called to store the settings. It should detect if any changes have been
          made and store those.
   \o matches() is used for the options dialog search filter.