[DJ1.9] Remove warning of not declaring explicit app_label

Example:

RemovedInDjango19Warning: Model class helios.models.Voter doesn't declare an explicit app_label and either isn't in an application in INSTALLED_APPS or else was imported before its application was loaded. This will no longer be supported in Django 1.9.

(cherry picked from commit 693acef9e4c3b093d5bf2bc1655e6f53a6dd4007)

helios/apps.py

+from django.apps import AppConfig
+
+class HeliosConfig(AppConfig):
+    name = 'helios'
+    verbose_name = "Helios"

helios/models.py

@@ -145,6 +145,9 @@ class Election(HeliosModel):
   # downloadable election info
   election_info_url = models.CharField(max_length=300, null=True)
 
+  class Meta:
+    app_label = 'helios'
+
   # metadata for the election
   @property
   def metadata(self):
@@ -650,6 +653,7 @@ class Election(HeliosModel):
 
     return prettified_result
 
+
 class ElectionLog(models.Model):
   """
   a log of events for an election
@@ -663,6 +667,9 @@ class ElectionLog(models.Model):
   log = models.CharField(max_length=500)
   at = models.DateTimeField(auto_now_add=True)
 
+  class Meta:
+    app_label = 'helios'
+
 ##
 ## UTF8 craziness for CSV
 ##
@@ -702,6 +709,9 @@ class VoterFile(models.Model):
   processing_finished_at = models.DateTimeField(auto_now_add=False, null=True)
   num_voters = models.IntegerField(null=True)
 
+  class Meta:
+    app_label = 'helios'
+
   def itervoters(self):
     if self.voter_file_content:
       if type(self.voter_file_content) == unicode:
@@ -780,7 +790,6 @@ class VoterFile(models.Model):
     return num_voters
 
     
-    
 class Voter(HeliosModel):
   election = models.ForeignKey(Election)
   
@@ -813,6 +822,7 @@ class Voter(HeliosModel):
 
   class Meta:
     unique_together = (('election', 'voter_login_id'))
+    app_label = 'helios'
 
   def __init__(self, *args, **kwargs):
     super(Voter, self).__init__(*args, **kwargs)
@@ -1003,6 +1013,9 @@ class CastVote(HeliosModel):
   # auditing purposes, like too many votes from the same IP, if it isn't expected
   cast_ip = models.GenericIPAddressField(null=True)
 
+  class Meta:
+      app_label = 'helios'
+
   @property
   def datatype(self):
     return self.voter.datatype.replace('Voter', 'CastVote')
@@ -1091,6 +1104,9 @@ class AuditedBallot(models.Model):
   vote_hash = models.CharField(max_length=100)
   added_at = models.DateTimeField(auto_now_add=True)
 
+  class Meta:
+    app_label = 'helios'
+
   @classmethod
   def get(cls, election, vote_hash):
     return cls.objects.get(election = election, vote_hash = vote_hash)
@@ -1108,6 +1124,7 @@ class AuditedBallot(models.Model):
 
     return query
 
+
 class Trustee(HeliosModel):
   election = models.ForeignKey(Election)
   
@@ -1140,6 +1157,7 @@ class Trustee(HeliosModel):
 
   class Meta:
     unique_together = (('election', 'email'))
+    app_label = 'helios'
 
   def save(self, *args, **kwargs):
     """

helios_auth/apps.py

+from django.apps import AppConfig
+
+class HeliosAuthConfig(AppConfig):
+    name = 'helios_auth'
+    verbose_name = "Helios Authentication"

helios_auth/models.py

@@ -35,6 +35,7 @@ class User(models.Model):
 
   class Meta:
     unique_together = (('user_type', 'user_id'),)
+    app_label = 'helios_auth'
 
   @classmethod
   def _get_type_and_id(cls, user_type, user_id):