Use new hemp bags

*Do not accept until the bags PR I sent has been merged bags!1*

* Updates `bags` version
* Bring in new `hemp` submodule (new dependency of `bags`)

See merge request !1

Make the softer woods, pine and aspen, 'flammable = 3'.
Correct inconsistent flammability of wood and stairs in relation
to all other solid wood nodes in MTGame.
Make the the softer woods, pine and aspen, 'choppy = 3'.