#819 Automatic dimension texts in the map and blue print export

[Tester7]

It would be useful if a automatic dimension text could measure out all walls, for inside and outside dimensions.
Additional even distance to corners for windows doors and light switches (all wall objects) could be added, and the size of the entire house plan.
The measuring tool now is imprecise and very time costly if you want measure out a entire plan, specially because it is not attached to wall corners and objects.
(In the present form it was almost useless for me.)