Restore Vanilla Mechanoid Droppods
Restores the ability for mechs to use droppods when raiding by reverting the 1.4 change to mechanoid raid arrival strategy.
Mechanoid raids will no longer be required to always Stage Attacks, and can therefore use the full list of arrival methods again. Uses the 1.3 weightings, so mechanoids will still often stage attacks (and immediate attacks are slightly rarer than in 1.3 on maps with water). Has no impact on clusters and the like.
