Add luacheck, update translations, replace ABMs, bug fixes (#1)

* luacheck, mt 5 translation, german translation, maintenance

* fix luacheck warnings

* Fix digital clock nodebox and texture

* Fix luacheck usage

* Add comment why fonts are not split into several lines

steles/config.lua

@@ -18,13 +18,13 @@
     along with steles.  If not, see <http://www.gnu.org/licenses/>.
 --]]
 
-local S = steles.intllib
+local S = steles.S
 
 steles.materials = {
-	'default:stone', 
-	'default:sandstone', 
+	'default:stone',
+	'default:sandstone',
 	'default:desert_stone',
-	'technic:marble', 
+	'technic:marble',
 	'technic:granite',
 }