The PNG charts in this commit are likely not up to spec. They were generated from Open Office Calc. They should probably be regenerated with Excel 2010. Unfortunately this is not something I am able to do at the moment.
One more item to note is that there is no mention of the range of applicability of the axis scale properties. Presumably charts such as pie charts circumvent any ambiguity by not having any axes to scale in the first place.
Please edit the PR to be based on the 2.3 branch.
Did my update to the PR accomplish that or should I redo the changes on the 2.3 branch locally and make another pull request?
The target is now 2.3 so I can merge but you should back out the changes locally as your default is now out of sync. For future PRs please always work on a numbered branch. The idea is that default/trunk/tip always reflects a stable release.