Use make step base for qmake projects

There are two differences that get introduced by this change:
- The configuration widget checks that there is a build configuration,
  but not if this build configuration is a QmakeBuildConfiguration. This
  should not matter, since Qmake is still the only supported project
  type for the qmake specific make step
- It removes the automaticallyAddedArguments(). As far as I can see this
  never had any effect anyhow, though. They were never actually added to
  the arguments.

Change-Id: I73be227a32117e462def38bdd040dbd7cbcc113f
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/projectexplorer/makestep.cpp

@@ -176,6 +176,10 @@ MakeStepConfigWidget::MakeStepConfigWidget(MakeStep *makeStep) :
         item->setFlags(item->flags() | Qt::ItemIsUserCheckable);
         item->setCheckState(m_makeStep->buildsTarget(item->text()) ? Qt::Checked : Qt::Unchecked);
     }
+    if (availableTargets.isEmpty()) {
+        m_ui->targetsLabel->hide();
+        m_ui->targetsList->hide();
+    }
 
     m_ui->makeLineEdit->setExpectedKind(Utils::PathChooser::ExistingCommand);
     m_ui->makeLineEdit->setBaseDirectory(Utils::PathChooser::homePath());