Limit nesting depth to 1000 and make it configurable.

tests/print_object.c

@@ -33,12 +33,11 @@ static void assert_print_object(const char * const expected, const char * const
 
     printbuffer formatted_buffer;
     printbuffer unformatted_buffer;
-    parse_buffer parsebuffer;
+    parse_buffer parsebuffer = { 0, 0, 0, 0 };
 
     /* buffer for parsing */
     parsebuffer.content = (const unsigned char*)input;
     parsebuffer.length = strlen(input) + sizeof("");
-    parsebuffer.offset = 0;
 
     /* buffer for formatted printing */
     formatted_buffer.buffer = printed_formatted;