Extract out conditional logic
Replace from_ids with overriding filter
Ensure cache isn't used with more than one filter kwarg
Update CHANGES
Helper methods should be static
DRY: wrap common logic in helper function
Remove from_ids wrapper method from manager
Remove from_ids lookup in attach_foreignkey
Merge pull request #16 from educreations/use-filter-instead-of-from_ids

Use filter instead of from_ids