Reviewing merge request #6: fix updating the heading label in snail execution mode
These changes fix the following bug:
How to reproduce the bug:
Make a block program that uses the 'heading' block and either the 'right', 'left', or 'arc' block. Run the program using the snail button.
Two minimal examples are here:
The 'heading' block shows something like 'heading = <bound method Turtle.get_heading of <TurtleArt.taturtle.Turtle instance at 0x...>>'.
The 'heading' block shows the numeric value of the heading, e.g., 'heading = 90'.
Commits that would be merged:
fix updating the heading label in snail execution mode