Update: fixed repr_tools to use auxiliary.has_shape() method
Fix: Fixed reverse slash problem in alembic cache export in repr_tools
Fix: Fixed possible reverse slash error in repr_tools.generate_ass()
New: Added anima.env.houdini.Houdini.set_environment_var() to be able to quickly add new variables
Fixed the Houdini.set_environment_variable() method
Fix: Fixed ``anima.env.houdini.Houdini.set_environment_variable()`` to correctly use a str value for the hscript command