+from django.conf import settings
+from django.core.mail import send_mail
+from django.db import models
+from django.db import transaction
+from django.utils.translation import ugettext_lazy as _
+from django.template.loader import render_to_string
+
+#from django.core.validators import validate_email
+
+try:
+ from django.contrib.auth import get_user_model
+ User = get_user_model()
+except ImportError:
+ from django.contrib.auth.models import User
+
+try:
+ from django.utils.timezone import now as datetime_now
+except ImportError:
+ datetime_now = datetime.datetime.now
+
+SHA1_RE = re.compile('^[a-f0-9]{40}$')