update json_object_new_string_len, json_escape_str (internal). Writer handles \x00 correctly

Added parse_null test. This does not change anything with how the parser handles \u0000 or null characters

This commit is addapted from one by Adomas Paltanavičius <adomas@leanholding.com>



git-svn-id: http://svn.metaparadigm.com/svn/json-c/trunk@63 327403b1-1117-474d-bef2-5cb71233fd97

test_null.test

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+# Common definitions
+if test -z "$srcdir"; then
+    srcdir="${0%/*}"
+    test "$srcdir" = "$0" && srcdir=.
+    test -z "$srcdir" && srcdir=.
+fi
+. "$srcdir/test-defs.sh"
+
+run_output_test test_null
+exit $?