Update tool icons to all use the same underlying "cube" shape and add bracing for structural icon and background walls for spatial icon.

src/blenderbim/docs/devs/installation.rst

@@ -71,7 +71,7 @@ restart Blender to see changes).
 
 For Linux or Mac:
 
-:: code-block:: console
+.. code-block:: console
 
     $ git clone https://github.com/IfcOpenShell/IfcOpenShell.git
     $ cd IfcOpenShell

src/ifcopenshell-python/ifcopenshell/file.py

@@ -252,7 +252,8 @@ class file(object):
         self.future = []
         self.transaction = None
 
-        file_dict[self.file_pointer()] = self
+        # Temporarily commented out until bot builds are available and tested to prevent user bugs.
+        # file_dict[self.file_pointer()] = self
 
     def set_history_size(self, size):
         self.history_size = size