Fixed bug in ExodusII_IO_Helper for discontinuous plots. The bug was due to an indexing error in the case of multiple subdomains. Also, DRY'd out the discontinuous vs. continuous code in ExodusII_IO_Helper.
Update github traffic.
Merge pull request #217 from dknez/exodus_discontinuous_fix

Fixed bug in ExodusII_IO_Helper for discontinuous plots.
Simplify call to plotting functions, don't need if block since we have
use_discontinuous as an argument now.