Various little tweaks to spandsp to stop warnings with newer compilers

Various little tweaks to spandsp to bring it into line with the master versions
Addition of Ademco Contact ID protocol processing to spandsp

libs/spandsp/m4/ax_misaligned_access_fails.m4

@@ -0,0 +1,33 @@
+# AX_MISALIGNED_ACCESS_FAILS(MACHINE, [ACTION-IF-MISALIGNED-FAILS], [ACTION-IF-MISALIGNED-OK])
+# -------------------------------------------------------------------------------------
+#
+# Check if a specified machine type cannot handle misaligned data. That is, multi-byte data
+# types which are not properly aligned in memory fail. Many machines are happy to work with
+# misaligned data, but slowing down a bit. Other machines just won't tolerate such data.
+#
+# This is a simple lookup amongst machines known to the current autotools. So far we only deal
+# with the ARM and sparc.
+# A lookup is used, as many of the devices which cannot handled misaligned access are embedded
+# processors, for which the code normally be cross-compiled. 
+#
+AC_DEFUN([AX_MISALIGNED_ACCESS_FAILS],
+[AS_VAR_PUSHDEF([ac_MisalignedAccessFails], [ac_cv_misaligned_access_fails_$1])dnl
+AC_CACHE_CHECK([if $1 fails on misaligned memory access], ac_MisalignedAccessFails,
+[case $1 in
+      arc | arm | arm[bl]e | arme[lb] | armv[2345] | armv[345][lb] \
+    | bfin \
+    | sparc \
+    | xscale | xscalee[bl] \
+    | arm-*  | armbe-* | armle-* | armeb-* | armv*-* \
+    | bfin-* \
+    | sparc-* \
+    | xscale-* | xscalee[bl]-* )
+        AS_VAR_SET(ac_MisalignedAccessFails, yes)
+        ;;
+    *)
+        AS_VAR_SET(ac_MisalignedAccessFails, no)
+        ;;
+esac])
+AS_IF([test AS_VAR_GET(ac_MisalignedAccessFails) = yes], [$2], [$3])[]dnl
+AS_VAR_POPDEF([ac_MisalignedAccessFails])dnl
+])# MISALIGNED_ACCESS_FAILS