Alpha 15 develop-2871

Moar fixes for Alpha 15 on our Steam unstable branch! Keep those bug reports coming….

Here’s what you’ll find in this release:
 * Fix for farmers not replanting after harvesting.
 * Fix for full storage containers not being reconsidered when an item is taken out, which means the containers are never refilled after item is taken out.
 * Get rid of free-standing columns when in xray mode.
 * Fix bug where furniture could not be placed on upper levels of in-progress buildings.
 * Fix hitching when starting and stopping the follow path mover consecutively. Also enable path visualization when chasing entities.
 * Fix for a edge case where crop’s harvestable flag was off from growing component’s growth stage, making the crop appear harvestable but it actually was not.
 * Prevent pathfinder renderer from generating a lot of garbage every time it updates the path. Fixes a huge memory leak when debug paths are turned on.
 * Fix wait encounters (e.g. crypt spawn necromancer) being triggered again in a loaded game.
 * Backwards compatibility for wall roofs.
 * Roofs walls now do not fill holes in floors.
 * Destroy orphaned bait traps.
 * Fix get_contiguous_regions bug.
 * Speed up camp placement by 10x.
 * Fix inventory-related save/load issues.
 * Improved logging for AI issues.
 * Added resource counts to template screen and building summary screen.