tidump: Clean up formatting and move to using the newly exported cmd73.h

Also adds TI-84 Plus CSE support and makes things a bit more robust by actually
checking return codes of functions for failure. Doesn't yet attempt to
retry failed pages, it seems the silverlink gets confused when you do so.

Will need further cleanup before merging with master.

TODO: Either remove or allow toggling of ram dumps and perhaps add a parameter
to only dump single pages for debugging or testing.