#691 Allow grouping and hiding dimensions just like furniture.

[Herman van Rink]

One usecase for this is to hide (most) dimentions just before printing, sometimes I prefer a printout with as little clutter as possibe.

A workaround is to just delete the dimentions before printing and revert to a saved version afterwards.

So just a nice to have ... if it's easy to implement.

[Twonky]

Other workaround: move dimensions to an additional layer at same elevation. You can include/exclude dimensions any time.