Let developers override more core pages by theme package

The concrete/single_pages/profile/* pages should be added as well. This is related to
http://www.concrete5.org/developers/bugs/5-6-1-2/overriding-single-pages-within-a-theme-package/

Problem is that these pages appear as installable page types in when inspecting a theme.

![bildschirmfoto 2013-08-04 um 06 10 40](https://f.cloud.github.com/assets/379246/906619/73d75fc4-fcbe-11e2-9602-99dfcba3c9f7.png)