Unify "missing compiler" and "missing build configuration" tasks

Everybody used to do their own thing...

Also unify the "Configuration is faulty" message we write into the
Application output window.

Change-Id: I0e5c4ec68155d66aa1d0ea53134b98917869e5c6
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/qmakeprojectmanager/qmakestep.cpp

@@ -286,7 +286,7 @@ bool QMakeStep::init()
                 canContinue = false;
         }
         if (!canContinue) {
-            emit addOutput(tr("Configuration is faulty, please check the Issues view for details."), BuildStep::MessageOutput);
+            emitFaultyConfigurationMessage();
             return false;
         }
     }