Arvados

I feel like it would be helpful to define a bigger picture strategy for catching and reporting SDK exceptions in our CLI tools. There's a lot that can go wrong besides socket errors, and it seems like if we figure out our desired approach, we can apply that consistently across all kinds of handleable exceptions without much extra effort.

And this may be out of scope, but given that patterns are starting to emerge in our tools, it doesn't seem totally unreasonable to start abstracting out a CLIToolBase class or something like that, which other tools can derive from. Having a common source for our common tasks like command-line parsing and error handling is starting to feel worthwhile.