Additional tools for working with IBE, including SIA access

PR includes tools for listing the valid / available data sets, missions, tables and a tool for querying the SIA component of IBE (which is the only programmatic way to get image access, as far as I can tell)
When I was mucking around earlier, it did do something, it just turned out to be something useless (it provided access to a wget.bat script)... so, yes, NotImplementedError sounds good.