Minor Changes:
* Placing a wire and holding shift will now allow you to create multiple wires to the same endpoint.
* When pasting an object, it is now allowed for sensors, pistons, nodes, welders, or magnets to overlap pre-existing structures that match the pasted object.
* Added option to have mods check for weld structure. Accessed by calling set_weld_checking(checker_index).
* An object's painting is preserved when replacing a basic block with an active one.
* The audio buffer size can be adjusted in settings (default: 2048). Smaller values will give less latency at the cost of possible stuttering.

Bug fixes:
* Fixed a fatal error occurring when a block which is adjacent to itself is deleted.
* Fixed a fatal error occurring when a portal closes on an extended piston then moves in a certain way.
* Fixed a fatal error occurring when a portal closes, opens, then closes again on an extended piston.
* Fixed a fatal error occurring when the user cuts a region which is welded to itself through a portal not in the cut region.
* Pistons no longer apply force to their arm when extended through a closed portal.
* Copying and cutting then pasting without moving at all now works properly.
* It is no longer possible to undo while the game is running.
* Vertically resizing a level with width zero can no longer break protected areas of the level.

There were some tiny patches prior to this one; these patches have been in place for a week, but for completeness, they fixed the following bugs:
* The game now stops listening for typing after renaming a save file.
* Resizing a level to zero width no longer loses track of the level's user region.
* The level "Locksmith" has appropriate resize information now.
* The default audio buffer size was changed from 512 to 2048.