Issue 1321, more accurate task count for qt4 and build groups

waflib/Tools/qt4.py

@@ -167,6 +167,9 @@ class qxx(Task.classes['cxx']):
 			tsk.set_inputs(h_node)
 			tsk.set_outputs(m_node)
 
+			if self.generator:
+				self.generator.tasks.append(tsk)
+
 			# direct injection in the build phase (safe because called from the main thread)
 			gen = self.generator.bld.producer
 			gen.outstanding.insert(0, tsk)