Simplify progress report during scanning

We now get less progress feedback, but in exchange, our progress job is
simpler. Previously, our progress bar would often get wonky towards the
end of the scan and I didn't have the energy to debug that.

Besides, people don't care about that level of progress feedback.

core/tests/engine_test.py

@@ -803,20 +803,6 @@ class TestCaseget_groups:
         r = get_groups([m1, m2, m3])
         eq_(3, len(r[0]))
 
-    def test_job(self):
-        def do_progress(p, d=''):
-            self.log.append(p)
-            return True
-
-        self.log = []
-        j = job.Job(1, do_progress)
-        m1, m2, m3 = get_match_triangle()
-        #101%: To make sure it is processed first so the job test works correctly
-        m4 = Match(NamedObject('a', True), NamedObject('a', True), 101)
-        get_groups([m1, m2, m3, m4], j)
-        eq_(0, self.log[0])
-        eq_(100, self.log[-1])
-
     def test_group_admissible_discarded_dupes(self):
         # If, with a (A, B, C, D) set, all match with A, but C and D don't match with B and that the
         # (A, B) match is the highest (thus resulting in an (A, B) group), still match C and D