Updated bootstrap with code for import_node; also made *.m files binary to git

.gitattributes

@@ -0,0 +1 @@
+*.m binary

bootstrap/modelling.alc

@@ -411,5 +411,9 @@ Void function construct_model():
 			local_name = input()
 			location = input()
 			export_node(location, global_models[local_name])
+		elif (command == "import_node"):
+			Element m
+			m = import_node(input())
+			dict_add(global_models, input(), m)
 		else:
 			log("Modelling error: did not understand command " + command)