While it probably won't address #184 since the batch script works without issue,
but I was unable to replicate this on my system, so this is at least an
intermediate step. Also do some refactoring around the export process, and don't
remove temp files in scripted mode if the last operation failed.
Port existing batch script behavior over to PowerShell, and switch over to a
command-based pattern like DBRepair.sh - that is, allow the user to pass in a
list of commands to be run automatically, or, if no commands are provided,
interactively allow the user to choose what to do.