move postprocessing of INCLUDEPATH into ProFileEvaluator::accept()

the rationale is that postprocessing which is done by the generators (in
some cases right at the point of emitting code to the makefile) should
be abstracted inside the "medium-level" class which also does the path
resolution done by the generators.

along the way we also make minor fixes to the processing:
- we pay attention to CONFIG+=no_include_pwd
- we add the build dir as well when shadow building

Change-Id: Ib389942fdc0470e05c1aa49e3615b6ac00241662
Reviewed-by: Daniel Teske <daniel.teske@theqtcompany.com>

src/plugins/qmakeprojectmanager/qmakeproject.cpp

@@ -538,10 +538,6 @@ void QmakeProject::updateCppCodeModel()
             }
         }
 
-        if (QmakeProFileNode *node = rootQmakeProjectNode())
-            templatePart->headerPaths += ProjectPart::HeaderPath(node->resolvedMkspecPath(),
-                                                         ProjectPart::HeaderPath::IncludePath);
-
         // part->precompiledHeaders
         templatePart->precompiledHeaders.append(pro->variableValue(PrecompiledHeaderVar));