Redone the acceptedStudentsExport functionality. The method has been renamed to exportStudentsWithProjects and retrieves the document_name and the new shipping address properties. Also it filters out all invalid projects or projects for wich the scope_path doesn't match the given scope_pa th_start. Also there is no more need to use the argument given to this method when adding the extra columns. The data is now prepared by one loop which uses the key present in the accepted_students dictionary for retrieving the data used by the extra columns.

# Until model subclassing is a possibility, a mixin class is used to add
# the necessary functions that may be contributed for geographic objects.
class GeoMixin:
    """
    The Geographic Mixin class provides routines for geographic objects,
    however, it is no longer necessary, since all of its previous functions 
    may now be accessed via the GeometryProxy.  This mixin is only provided
    for backwards-compatibility purposes, and will be eventually removed
    (unless the need arises again).
    """
    pass