Rip out "retain older" feature that never worked reliably.

Rip out "retain older" feature that never worked reliably.

Overly complicated the code and would far too often leave me wondering why it failed to record recent history.

Change to a "just whatever's in the server" mode again.
Improve reporting of most recently fetched event in UI.
Add "need to relog/exit to actually write file" at end of fetch.
Upgrde debug brakes to full-time release brakes: only "complete" a guild once per "Save Now" invocation.