Adapt to lightning -> lightening name change

* libguile/jit.c: Include lightening.h.
* libguile/Makefile.am: Adapt.

libguile/lightning/tests/Makefile

@@ -1,24 +0,0 @@
-TESTS=$(sort $(basename $(wildcard *.c)))
-
-CC = gcc
-CFLAGS = -Wall -O0 -g
-
-all: $(addprefix test-,$(TESTS))
-
-check: all
-	@echo "Running unit tests..."
-	@set -e; for test in $(TESTS); do \
-	  echo "Testing: $$test"; \
-	  ./test-$$test; \
-	done
-	@echo "Success."
-
-lightening.o: ../lightening.h ../lightening/*.c
-	$(CC) $(CFLAGS) $(CPPFLAGS) -I.. -o lightening.o -c ../lightening/lightening.c
-
-test-%: %.c lightening.o test.h
-	$(CC) $(CFLAGS) $(CPPFLAGS) -I.. -o $@ lightening.o $<
-
-clean:
-	rm -f $(addprefix test-,$(TESTS))
-	rm -f lightening.o