Add ability to lock layout (prevent acciental movement of walls, etc)

[ChiefTea]

Anyone else having accidents with selling off flags, statues and moving walls? Even accidentally boosting things?

It would be nice if there was a "lock" switch that can toggle the map layout to be locked so that none of this can happen. This way we can safely focus on training troops with the peace of mind that we won't accidentally cancel a building upgrade or sell off an obstacle. Sheesh!

[zoelem]

How could you accidently do any of this stuff other than moving walls? The whole screen majorly changes for all of them except for moving the wall, which can get annoying but isnt a problem.