Implement ITU-T I.460 multiplex / demultiplex

This implements a multiplexer and de-multiplexer for the ITU-T I.460
standard.  The latter covers the transmission of sub-slots of 32/16/8k
inside 64k timeslots.

Change-Id: Id522f06e73b77332b437b7a27e4966872da70eda
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 0d0327a..5e810e6 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -35,6 +35,7 @@
 		 context/context_test					\
                  gsm0502/gsm0502_test					\
                  dtx/dtx_gsm0503_test					\
+                 i460_mux/i460_mux_test					\
 		 $(NULL)
 
 if ENABLE_MSGFILE
@@ -269,6 +270,9 @@
 exec_exec_test_SOURCES = exec/exec_test.c
 exec_exec_test_LDADD = $(LDADD)
 
+i460_mux_i460_mux_test_SOURCES = i460_mux/i460_mux_test.c
+i460_mux_i460_mux_test_LDADD = $(LDADD) $(top_builddir)/src/gsm/libosmogsm.la
+
 # The `:;' works around a Bash 3.2 bug when the output is not writeable.
 $(srcdir)/package.m4: $(top_srcdir)/configure.ac
 	:;{ \
@@ -346,6 +350,7 @@
 	     gsm0502/gsm0502_test.ok \
 	     dtx/dtx_gsm0503_test.ok \
 	     exec/exec_test.ok exec/exec_test.err \
+	     i460_mux/i460_mux_test.ok \
 	     $(NULL)
 
 DISTCLEANFILES = atconfig atlocal conv/gsm0503_test_vectors.c