Doc: list Qt Quick Controls with links to docs

Change-Id: I94f3750851fac7c3fc7b975fc68d982e6c819273
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>
Doc: update screenshots that illustrate states

The number icons changed color from blue to green
to fit the new template, so all screenshots with
numbers must be updated.

Change-Id: I039d6ee7ac150e8535e61e6ca1edfd08cb61ed91
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>