BUG: CubeGrid.Dispose() special case issue when deleting blocks individually

[Tyrsis]

I have run into some fringe cases where ships that are built strangely (have cubeblocks at the end of the cubeblock list that is attached to the grid with only 1 block) will sometimes break off before being disposed and create their own cubegrid (like they were shot off the ship). This causes what I like to call, "float parts". Which in itself isn't too bad unless you're trying to bring back an entity in the same position from where it was removed from. Then that floating part becomes basically a bomb that destroys the entity that appears on it.

In the API if you remove the block by block deletion, it still removes the grid seemingly fine, and solves the issue.

[fvgoulet]

@Tyrsis Please provide a step by step list of actions to be done to reproduce the issue.