Merge branch 'master' into turtle-suspensions
Turtle rewrite

complete rewrite of the turtle module
Updated float/int cast methods
Adds an undo stack

Implementation of undo command (max 1000)
Must be enabled by setundobuffer(N) where 0 < n < 1000
Fixed getCoordinates for case when a vector is passed in
Merge branch 'turtle-suspensions' of https://github.com/trinketapp/skulpt into trinketapp-turtle-suspensions
Merge branch 'trinketapp-turtle-suspensions' into turtledev