TBH, the repository is a mess which needs to be restructured, and the hosting platform is a mess too, so it needs to be moved to a better platform.
Regardless, here’s a rough process for finding the changes… First, here’s the base URL for the repository:
https://launchpad.net/flashlight-firmware
From there, click the “Code” tab at the top:
https://code.launchpad.net/flashlight-firmware
This shows a list of all the code branches, in order of most recent first (except for trunk, which is pinned to the top even if it’s old). The most recent one is the multi-channel branch, since I’ve been working on converting everything to a new method of handling multiple power channels and multiple sets of LEDs. It’s also the only one with a date within the range you were looking for:
https://code.launchpad.net/~toykeeper/flashlight-firmware/multi-channel
From there, scroll down a bit to see recent revisions. There have been a bunch though, so click the “All revisions” link at the bottom to see more.
https://bazaar.launchpad.net/~toykeeper/flashlight-firmware/multi-channel/changes
… and this has full details on what changed.
The way it works now isn’t a good way to do it… it’s a lazy way to do things, and I should do better. I’ve just got a huge pile of things waiting to be done. Gotta finish the multi-channel branch, which involves sort of rewriting the code for all ~70 supported lights. Merge all the outstanding branches to simplify things for an upcoming migration. Export FSM to its own repository. Convert the repo to git, and put it on github. Update links and documentation to point to the new host. Rewrite the build configuration system to organize the files better, and make it easier to find and understand things. And hopefully make time to work on user-visible features too, and adding support for new lights.
Anyway, I hope this at least helps with finding what changed. And to get info about a particular light, look for its “cfg-.h" file. It should have details about how things are configured, and references to other files with additional details (like a "hwdef-.h” file).