Feature request: Download only updates (no FeaturesOnDemand, MetadataESD, Uup)

[mrpijey]

As the title say, it would be great with a flag where it skips FeatureOnDemand, MetadataESD and UUP as they are identical between main builds while grabbing everything else.

Right now every time there's a new build of an RTM branch it always re-downloads all the other files which is unnecessary if you already have a full set from the previous build.

[gus33000]

Thats a great idea, I will try to implement this over the weekend. Thanks!