Alpha 11 release-447

Bug fixes

 * Fixed bug tracking the occupied space in stockpiles which could cause hearthlings to randomly pick up and put down items.
 * Fixed bug in stockpile filters when all items are acceptable.
 * Fixed bug that caused undo to create holes in buildings.
 * Fixed bug that caused items to not undeploy.
 * Fixed bug that caused ladders to be unremovable.
 * Fixed errors when actions could not be completed.
 * Fixed error when trying to pick up an item off a table when the item has already been picked up.
 * Fixed promotion talismans no longer glowing after load.
 * Prohibit digging through the bottom of the world.
 * Fixed error using instabuild and instamine when a building or mining zone was not selected.
 * Wolves no longer get stuck in the ground (While trying to equip hearthling gear stolen by goblin thieves; bad wolves! Need opposable thumbs first, and smaller torsos!)

Other Changes

 * Improved pathfinding and task scheduling performance when there are lots of ladders around.
 * Improved performance when there are a large number of items in stockpiles.
 * Make the camera point north again when choosing a settlement location.