e1cap_dump: Implement functional HDLC decode of super-channel

Finally the bit ordering and bit format of the SuperChannel has been
figured out.
* the data as read from DAHDI must be flipped (0->1 / 1->0). why?
* the data must be read lsb-first when converting into a bit-buffer

We are now getting the following output e.g. for a OM2000 "TX
Configuration Request" message:
fa 03 8a 8a 80 80 00 13 00 b0 0b 00 ff 01 20 00 2e 2b 1c 00 06 01 95 81 76 00 e9 bf
^ lapd hdr  ^ OML    ^l ^OM2000 TX Config Req for 43 dBm
diff --git a/src/Makefile b/src/Makefile
index 734c658..25c00d6 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -1,16 +1,19 @@
 CFLAGS=-g -Wall
 LDFLAGS=-losmocore -losmogsm -losmovty -losmoabis -ltalloc
 
-all: osmo-e1-recorder osmo-e1cap-dump
+all: osmo-e1-recorder osmo-e1cap-dump hdlc-test
 
 osmo-e1-recorder: e1_recorder.o storage.o vty.o
 	$(CC) $(LDFLAGS) -o$@ $^
 
-osmo-e1cap-dump: e1cap_dump.o storage.o
+osmo-e1cap-dump: e1cap_dump.o storage.o flip_bits.o hdlc.o
+	$(CC) $(LDFLAGS) -o$@ $^
+
+hdlc-test: hdlc.o hdlc-test.o
 	$(CC) $(LDFLAGS) -o$@ $^
 
 %.o: %.c
 	$(CC) $(CFLAGS) -o $@ -c $^
 
 clean:
-	@rm *.o osmo-e1-recorder
+	@rm *.o osmo-e1-recorder osmo-e1cap-dump