Generic project manager: assume C++11 for cxxVersion.

Change-Id: I40bd4b73d93eaf71d1dfbf7c9c1572f0cb796bd9
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/plugins/genericprojectmanager/genericproject.cpp

@@ -255,6 +255,7 @@ void GenericProject::refresh(RefreshOptions options)
                                     SysRootKitInformation::sysRoot(k));
         }
 
+        part->cxxVersion = CppTools::ProjectPart::CXX11; // assume C++11
         part->includePaths += allIncludePaths();
         part->defines += m_defines;