initial work on adding models for starring repos.

I'm sick of using `git stash`.

data/model/legacy.py

@@ -2385,3 +2385,54 @@ def archivable_buildlogs_query():
     .where((RepositoryBuild.phase == BUILD_PHASE.COMPLETE) |
            (RepositoryBuild.phase == BUILD_PHASE.ERROR) |
            (RepositoryBuild.started < presumed_dead_date), RepositoryBuild.logs_archived == False))
+
+
+def star_repository(user, repository):
+  """ Stars a repository. """
+  star = Star.create(user=user.id, repository=repository.id)
+  star.save()
+
+
+def unstar_repository(user, repository):
+  """ Unstars a repository. """
+  try:
+    star = (Star
+            .select()
+            .join(Repository)
+            .switch(Star)
+            .join(User)
+            .where(Repository.id == repository.id, User.id == user.id)
+            .get())
+  except Star.DoesNotExist:
+    raise DataModelException('Star not found.')
+
+  star.delete_instance()
+
+
+def get_user_starred_repositories(user, limit=None, page=None):
+  """ Retrieves all of the repositories a user has starred. """
+  query = (Repository
+           .select()
+           .join(Star)
+           .join(User)
+           .where(User.id == user.id)
+           .order_by(Star.created))
+
+  if page and limit:
+    query = query.paginate(page, limit)
+  elif limit:
+    query = query.limit(limit)
+
+  return query
+
+
+def repository_is_starred(user, repository):
+  """ Determines whether a user has starred a repository or not. """
+  try:
+    (Star
+     .select()
+     .where(Star.repository == repository.id, Star.user == user.id)
+     .get())
+    return True
+  except Star.DoesNotExist:
+    return False