Allow updating of configuration or file list separately

Now it will only update the list of files when you edit [project].files,
and only reparse all files when you edit [project].config or
[project].includes. When updating the file list it will only parse the
added files.

src/plugins/cmakeprojectmanager/makestep.cpp

@@ -202,7 +202,6 @@ void MakeStep::removeDirectory(const QString &dir)
         m_openDirectories.remove(dir);
 }
 
-
 CMakeProject *MakeStep::project() const
 {
     return m_pro;