isdn: Add V.110 encoder/decoder

V.110 defines a B-channel protocol for transmission of synchronous and
asynchronous serial data of V-series interfaces via terminal adapters
over ISDN.

Let's add (unoptimized but easy to debug) functions for encoding and
decoding of V.110 frames for various bit-rates.

Related: OS#1572
Change-Id: I1b5fd3847d3bfb0a0f763e0574893962ec699680
diff --git a/tests/testsuite.at b/tests/testsuite.at
index e447cdc..39cf54a 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -490,3 +490,15 @@
 cat $abs_srcdir/iuup/iuup_test.ok > expout
 AT_CHECK([$abs_top_builddir/tests/iuup/iuup_test], [0], [expout], [ignore])
 AT_CLEANUP
+
+AT_SETUP([v110_test_frame])
+AT_KEYWORDS([v110_test_frame])
+cat $abs_srcdir/v110/test_frame.ok > expout
+AT_CHECK([$abs_top_builddir/tests/v110/test_frame], [], [expout],[])
+AT_CLEANUP
+
+AT_SETUP([v110_test_ra1])
+AT_KEYWORDS([v110_test_ra1])
+cat $abs_srcdir/v110/test_ra1.ok > expout
+AT_CHECK([$abs_top_builddir/tests/v110/test_ra1], [], [expout],[])
+AT_CLEANUP