@mikesan, if you follow the link given by Ingo, at the right of each commit you'll see a suite of 7 characters, which are the first 7 characters of the Changeset number. For example, the last commit's changeset starts with
f7af57d, and you'll find these characters in the current build's
AboutThisBuild.txt because I made it from this stage.
If you still have the previous build I uploaded, find the changeset in it's
AboutThisBuild.txt, read the first 7 characters of its changeset, then follow Ingo's link and locate the corresponding commit: you'll then see what changes have been commited between the two version.