script generalization tweaks for ASGS

[wwlwpd]

Creating as a placeholder for the ASGS integration work. @zcobell if you'd like me to create more specific issues, let me know. I intend on addressing them. So far the only issue I've found is the following:

We need to be able to pass in $JOBLAUNCHER while in asgs shell, have the start of the branch at:

• wwwpwd-dev@d5d3930
• https://github.com/wwwpwd-dev/adcirc-cg-testsuite/commits/generalize-joblauncher

The associated ASGS issue is, https://github.com/jasonfleming/asgs/issues/344.