Checking in widgetset - xx.manifest file keeps changing

Up until now, we have not checked in the widgetsets in our project, meaning that whenever we update the vaadin version or create a branch, everyone has to regenerate it.
Fair enough, it only takes time.
But, when you start to throw addon licenses into the mix it becomes a bit awkward. 

So, now I am attempting to check in the generated widgetsets.
This way, only a few in out team need to worry about licenses.

So far I have seen one problem, and that is with touchkit. The widgetset generated from that contains a set of manifest files: aosp.manifest, gecko1_8.manifest, ie10.manifest, safari.manifest.

These again has a line at the top that says:
# Build timeMon Jan 16 16:28:03 CET 2017

When my colleague did an update and a refresh in Eclipse, one of these comments changed.

Files that change for no good reason are awkward to have in a version control system.
Does anyone have any idea of how to avoid this?
 

Are you using SuperDevMode?
 

We're not using SuperDevMode at the moment, no, and my colleague with the changed file has never used it.

I see that my colleague has Vaadin Plugin 2.3.6, while I have 3.0.0, if that makes any difference.

I suggest updating. I seem to recall there was a very similar issue in an older version of Vaadin Designer, which got resolved quickly once we noticed it was messing up version control.

-Olli