CMake: Move code from CMakeProject into BuildDirManager

This is in preparation for having support for cmake's server
mode.

Change-Id: I6cc04fe7c5132c491c3f3c0f46560b8ad88808e8
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/cmakeprojectmanager/cmakebuildconfiguration.h

@@ -52,8 +52,6 @@ public:
     CMakeBuildConfiguration(ProjectExplorer::Target *parent);
     ~CMakeBuildConfiguration();
 
-    void cmakeFilesChanged();
-
     bool isEnabled() const override;
     QString disabledReason() const override;