forms: rename _has_changed to has_changed (#111)
forms: rename _has_changed to has_changed (#111)

The _has_changed had been deprecated in Django 1.6 and compatibility shim for
it has been removed way back in 1.10. Fixes the regression and restores
the change detection behavior.

Co-authored-by: ort <f6d52ade0dd78fb10946f3e8aed90c87fc746af4@users.noreply.github.com>
disqus/django-bitfield