Improve the placement logic for slabs, etc (#160)

Co-authored-by: Hugo Locurcio <hugo.locurcio@hugo.pro>

CHANGELOG.md

@@ -9,22 +9,25 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Added
 
-- Clean Glass versions of Trap and (Super) Glowing Glass
+- Clean Glass versions of Trap and (Super) Glowing Glass.
+- Compressed desert cobblestone.
+
+### Changed
+
+- Revised placing strategy that takes into account which side of the face
+  (top/bottom for horizontal, left/right for vertical placement) is being clicked.
+  Aux (sprint/special, default E) key can be used to place the node with the orientation
+  it would have if placed from the other side.
+  When placing nodes next to nodes of the same gategory (e.g.slab to slab) the other
+  node's orientation is copied, flipping it placing on top or below an upright or
+  upside-down node. In this case the aux key will disable the special processing of
+  same-category nodes.
 
 ### Removed
 
 - Legacy Stairs+ conversion code.
   - It was only required to import worlds last edited before Q3 2013.
 
-### Changed
-
-- Switch to GitHub Actions.
-  - Benefits include faster responses.
-
-### Added
-
-- Compressed desert cobblestone.
-
 ## [2.0.0] - 2019-11-25
 
 ### Added