Capture geometric (or any other external package error) and wrap with QCOPException class

[coltonbh]

When geomeTRIC raises an exception (e.g., failed to converge) we get various ChemCloud server errors (same issue Umberto was having). This is because the exception is not caught and raises under the QCOP banner so when the ChemCloud server re-raises the error from celery (result.ready()) the exception class doesn't exist because geometric is not installed on the server so an exception is raised and the server returns a 500.

I need to capture all external package exceptions--like QCEngine exceptions--and wrap them in a QCOP exception class.

[coltonbh]

Closed by #17