Do you use Git(hub)?
I do, but mostly only for my own code. I could probably dig into the dropbox changelog if anything particular comes up, though. That said, I probably overspoke - thinking back on it I probably only extended the boards.txt file for additional BOD levels and clocks, and I made up a separate bundle of the Arduino environment with the updated toolchain to get past the PCREL linker error. Part of my goal this week is to try to get my local Arduino toolchain back to as close to the distribution defaults as possible again, then re-apply changes in a controlled and documented manner so I know what I've all changed.