'scope' field moved from TaskTag to the parent class.

TaskArbritraryTag now has auto_delete set to True by default. Reviewed by: Lennard de Rijk

Adds a new property to taggable which automatically deletes an empty tag. Reviewed by: Lennard de Rijk

Fixed an error with the task_history not being loaded when it was empty.

Fixed 'Register as a student' link problem for GHOP program. Params and new_params in student view are also sub-merged now, so the apply pattern may be used by GHOP student view.

Lists of student tasks view does not use pagination. Also some minor stylish issues fixed.

Accidental module change in settings.py fixed.

List view of all tasks for a GHOP student. Link 'List my tasks' in the GHOP program submenu is now active for a GHOP student and displays all tasks (grouped by organizations) which the user is involved in.

getListContentForData function added to lists helper. It allows to manually set a list of entities which is to be displayed on the view. Previously, the only function was getListContent, but it retrived data on its own by a single query. The new function can be useful whenever it is impossible or very awkward to obtain entities in such a way (for example more sophisticated SQL statements). Additionally, the getListContent function is reconstructed so that it collects the data first and then calls getListContentForData.

HtmlSanitizer becomes Python 2.6 compatible. The Cleaner class must not have any arguments when calling __init__ function for the object class, because in this case Python 2.6 raises TypeError (while previous versions just ignored them).