Fix model warnings and deprecations

1. ForeignKey with unique -> OneToOneField
2. IPAddressField -> GenericIPAddressField
3. Fix fields with default=datetime.now() which gives server start time,
   not the insert time (clearly this default was never used, and the
   field was always explicitly set, but it should still not be incorrectly
   defined)

pgweb/core/models.py

@@ -2,8 +2,6 @@ from django.db import models
 from django.contrib.auth.models import User
 from pgweb.util.misc import varnish_purge
 
-from datetime import datetime
-
 TESTING_CHOICES = (
 	(0, 'Release'),
 	(1, 'Release candidate'),
@@ -121,7 +119,7 @@ class Organisation(models.Model):
 	phone = models.CharField(max_length=100, null=False, blank=True)
 	orgtype = models.ForeignKey(OrganisationType, null=False, blank=False, verbose_name="Organisation type")
 	managers = models.ManyToManyField(User, null=False, blank=False)
-	lastconfirmed = models.DateTimeField(null=False, blank=False, default=datetime.now())
+	lastconfirmed = models.DateTimeField(null=False, blank=False, auto_now_add=True)
 
 	send_notification = True
 
@@ -161,7 +159,7 @@ class ImportedRSSItem(models.Model):
 
 # Extra attributes for users (if they have them)
 class UserProfile(models.Model):
-	user = models.ForeignKey(User, null=False, blank=False, unique=True, primary_key=True)
+	user = models.OneToOneField(User, null=False, blank=False, primary_key=True)
 	sshkey = models.TextField(null=False, blank=True, verbose_name="SSH key", help_text= "Paste one or more public keys in OpenSSH format, one per line.")
 	lastmodified = models.DateTimeField(null=False, blank=False, auto_now=True)