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.  
Okay, I think my last answer could be confusing, so to clear this up:
Wenqing is right, ```Node::getID()``` returns ```Node::_id```. However, this variable only exists because it is computationally expensive to find the index in the node vector from the node object itself, so we added the ID to keep this information. And here Nori is right, ```getID()``` should always return the actual index of a node in the node vector, because algorithms depend on this. ID should only be non-consistent with actual IDs in a local context (i.e. once you leave your specific method IDs should have been resetted). If you need identifiers that do not actually signify the current position in the node array, use a vector as map, as suggested in my answer above.