checkIsHostForProgram function takes a new 'logic' argument.
It determines which logic should be used to look up for program entity. If the argument is not given, the standard program_logic will be used.
"""
Field-like classes that aren't really fields. It's easier to use objects that
have the same attributes as fields sometimes (avoids a lot of special casing).
"""
from django.db.models import fields
class OrderWrt(fields.IntegerField):
"""
A proxy for the _order database field that is used when
Meta.order_with_respect_to is specified.
"""
name = '_order'
attname = '_order'
column = '_order'