Allow to adjusting nodes of multipolygon objects

[Sirorezka]

Description

Hi,

I would propose to adjust some of the settings that make working with multipolygon buildings easier.

Let's say that you have two areas and you combined them into multipolygon and assigned a type to this new object. In my case I've created two building-parts and then combined them into the building using multipoylgon:

object 1:

building=yes
type=multipolygon

object 2: building:part=yes object 3: building:part=yes

Here is an image of my object:

Now when I try to move any free nodes or linked nodes in the same relation you will get an error: Areas cannot cross over themselves. Picture below illustrate which edges of the multipolygon I was trying to move:

Desired behaviour:

• You should be able to move free nodes of the areas even if they are part of the bigger relation (at least for buildings).
• You should be able to move linked nodes if they are part of the same relation. And if both objects are only in single relation. I.e. in my case node is shared between two children of single multipologyon builidng.

Screenshots