ufz/ogs — pull request #512 by wenqing (2014-10-16 10:51:18+00:00)
Title: New class PETScWallClockTimer and Modifications in classes of RunTime and CPUTime

As Dimm suggested. I subtracted this PR from #487 specially for classes of ``PETScWallClockTimer``, ``RunTime``, and ``CPUTime``. With the modifications in ``RunTime`` and ``CPUTime``, member ``stop()`` was removed. @TomFischer and @endJunction ,please take a look.

PR #487 will be closed temporarily due to the ``reset node ID`` issue, and it will be reopened once a FEM (say for a simple elliptic problem ) is completed in the official repository.