Allow hiding a user from the frontpage task list.

This adds new query arguments to the taskList hub xmlrpc endpoint, and then
makes use of those arguments in koji-web.  A new optional configuration value
is added for koji-web: `HiddenUser`, which can be used to specify which user
account should be hidden.  This could be useful for deployments that have a
continuous-integration account, the spam from which makes the frontpage
difficult to read.

Unit test cases are also added for some functions of the hub taskList endpoint.

Signed-off-by: Ralph Bean <rbean@redhat.com>

tests/test_hub/test_listing.py

@@ -0,0 +1,60 @@
+import unittest
+import mock
+
+import kojihub
+
+
+class TestListing(unittest.TestCase):
+    def setUp(self):
+        self.hub = kojihub.RootExports()
+        self.standard_processor_kwargs = dict(
+            tables=mock.ANY,
+            columns=mock.ANY,
+            values=mock.ANY,
+            joins=mock.ANY,
+            clauses=mock.ANY,
+            opts=mock.ANY,
+            aliases=mock.ANY,
+        )
+
+    @mock.patch('kojihub.QueryProcessor')
+    def test_list_tasks_basic_invocation(self, processor):
+        generator = self.hub.listTasks()
+        results = list(generator)  # Exhaust the generator
+        processor.assert_called_once_with(**self.standard_processor_kwargs)
+
+    @mock.patch('kojihub.QueryProcessor')
+    def test_list_tasks_by_owner(self, processor):
+        generator = self.hub.listTasks(opts={'owner': 1})
+        results = list(generator)  # Exhaust the generator
+        arguments = self.standard_processor_kwargs.copy()
+        arguments['clauses'] = ['owner = %(owner)i']
+        processor.assert_called_once_with(**arguments)
+        self.assertEqual(results, [])
+
+    @mock.patch('kojihub.QueryProcessor')
+    def test_list_tasks_by_not_owner(self, processor):
+        generator = self.hub.listTasks(opts={'not_owner': 1})
+        results = list(generator)  # Exhaust the generator
+        arguments = self.standard_processor_kwargs.copy()
+        arguments['clauses'] = ['owner != %(not_owner)i']
+        processor.assert_called_once_with(**arguments)
+        self.assertEqual(results, [])
+
+    @mock.patch('kojihub.QueryProcessor')
+    def test_list_tasks_by_arch(self, processor):
+        generator = self.hub.listTasks(opts={'arch': ['x86_64']})
+        results = list(generator)  # Exhaust the generator
+        arguments = self.standard_processor_kwargs.copy()
+        arguments['clauses'] = ['arch IN %(arch)s']
+        processor.assert_called_once_with(**arguments)
+        self.assertEqual(results, [])
+
+    @mock.patch('kojihub.QueryProcessor')
+    def test_list_tasks_by_not_arch(self, processor):
+        generator = self.hub.listTasks(opts={'not_arch': ['x86_64']})
+        results = list(generator)  # Exhaust the generator
+        arguments = self.standard_processor_kwargs.copy()
+        arguments['clauses'] = ['arch NOT IN %(not_arch)s']
+        processor.assert_called_once_with(**arguments)
+        self.assertEqual(results, [])