Adding _opened flag to ExodusII helper.
Use C++ style casts.
Make spacing consistent in for loops.
Removing apparently redundant calls to Exodus_IO_Helper::get_time_steps().
Removing old comments.
Generalize NamesData object to take a string length.
Have ExodusII_IO_Helper::write_information_records() use the NamesData object.
Reformatting in:
* ExodusII_IO::write_element_data()
* ExodusII_IO_Helper::write_element_values()

Removing redundant active elem check and adding docs.
Adding MeshSerializer object to ExodusII_IO::write_element_data().

This function only works with SerialMeshes, similarly to the way
that ExodusII_IO::write() and ExodusII_IO::write_timestep() currently
work.
Use a macro to check error codes in the Exodus reader.

This way, stack traces go back to the line where they originated,
rather than the check_err() function.
Merge branch 'exII_refactor'