#64 and #473 are examples of complaints about this.

Currently, ShellJS will kill the process if it encounters an unexpected ("internal") error. Ideally, the commands should all catch these before they arise, but since nothing is ever perfect so sometimes utilities fail for various reasons (permissions errors are a big reason).

It'd be great if ShellJS threw an exception instead of killing the process, since this would at least allow users the chance to catch the exception in their code. If the exception is left uncaught at the top-level, this would kill the process anyway as it currently does. This could have significantly different behavior if thrown inside of a try-catch, however, so this would be a breaking change.