Add unit::noGroup and Get/SetUnitNoGroup

[saurtron]

Work done

• Add noGroup flag for units
• Add lua Get/SetUnitNoGroup

Remarks

• Implemented this so blocking units being added to groups can be controlled in the same way as to selection
• Units in a group, even if they could be unselectable due to noSelect will affect the group centroid.

[lhog]

Looking ok to merge, though I struggle with the use case a little bit.
In what cases you'll want units to be selectable by not group-able. Wouldn't it look like a bug?

[saurtron]

Looking ok to merge, though I struggle with the use case a little bit. In what cases you'll want units to be selectable by not group-able. Wouldn't it look like a bug?

you can try #1824 if you want xd, personally got tired of fighting for that so I went for the other possible path which is this + #1850

[lhog]

Looking ok to merge, though I struggle with the use case a little bit. In what cases you'll want units to be selectable by not group-able. Wouldn't it look like a bug?

you can try #1824 if you want xd, personally got tired of fighting for that so I went for the other possible path which is this + #1850

This ones are better than #1824
So the only reason to have this is to precisely control behavior of groups membership, for the use cases we're yet to see?

[sprunk]

Use case for selectable but ungroupable would be something like goblin shops from wc3. But more importantly there's use cases for groupable but unselectable which means groupability and selectability are separate states which warrant atomic calls.