-regular page doesn't list the group members, allowing extra content
to be listed and gives control on the layout of information
-renamed "Installation" to "Building Qt Sources" as it is a more precise
 name
-Added links to the "Building Qt Sources" page where it makes sense.

Change-Id: I074bc5c17edf2bc096bcfc8f6d102b469929ede0
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>
Reviewed-by: Nico Vertriest <nico.vertriest@digia.com>
Reviewed-by: Martin Smith <martin.smith@digia.com>