Add new LAPDm RAW port

This is a Test Component which sits on top of L1CTL (which in turn is on
top of the Unix Domain Socket Test Porrt).  It performs LAPDm message
encoding/decoding, so we can use the regular send() / receive() methods
and associated template matching to send/receive/match LAPDm in a
comfortable way.
diff --git a/lapd/LAPDm_Types.ttcn b/lapd/LAPDm_Types.ttcn
index 522aa4d..988e015 100644
--- a/lapd/LAPDm_Types.ttcn
+++ b/lapd/LAPDm_Types.ttcn
@@ -116,7 +116,7 @@
 	};
 
 	template LapdmCtrl t_LapdmCtrlUA(template boolean f) modifies t_LapdmCtrlU := {
-		u := { u2 := '01'B, p_f := f, u := '011'B }
+		u := { u2 := '00'B, p_f := f, u := '011'B }
 	};
 
 	external function dec_LapdmAddressField(in octetstring stream) return LapdmAddressField
@@ -154,16 +154,18 @@
 	type record LapdmFrameB {
 		LapdmAddressField	addr,
 		LapdmCtrl		ctrl,
-		LapdmLengthIndicator	len,
+		uint6_t			len,
+		boolean			m,
+		uint1_t			el (1),
 		octetstring		payload
-	} with { variant "" };
+	} with { variant (len) "LENGTHTO(payload)"
+		 variant "FIELDORDER(msb)" };
 
 	external function enc_LapdmFrameB(in LapdmFrameB si) return octetstring
 		with { extension "prototype(convert) encode(RAW)" };
 	external function dec_LapdmFrameB(in octetstring stream) return LapdmFrameB
 		with { extension "prototype(convert) decode(RAW)" };
 
-
 	/* Format B4 */
 	type record LapdmFrameB4 {
 		LapdmAddressField	addr,