Fix fitViewportToMapItemsRefine

The item counter was broken. Therefore the bounding box calculation
only worked under certain circumstances.
This commit removes the circle special case calculation, which is
superfluous, and treats all map items the same way.

Change-Id: Ida0a6cf695fb151132bc867eb30ecb834a5bf6c5
Reviewed-by: Fabian Bumberger <fbumberger@rim.com>
Reviewed-by: Aaron McCarthy <mccarthy.aaron@gmail.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>