Class for parallel reading of partitioned mesh data

Along with commit 4cda158,  member function ``stop()`` of class CPUTime and RunTime were removed, and the calling of the function has been removed in the related files.  
yes, you are right. and in case ```rank==0``` you also save a comparison if you use the ```else``` clause.
the exclusive ```if``` for the 2nd case would only make sense if there were some overlap in the result sets...