- speedup of IS_CHAR like macros, significant overall improvement

- More interfaces for new I/O functions: xmlNewIOInputStream,
  xmlParserInputBufferCreateIO, xmlCreateIOParserCtxt
- added I/O test to xmllint
Daniel

xmlIO.c

@@ -635,6 +635,35 @@ xmlParserInputBufferCreateFd(int fd, xmlCharEncoding enc) {
     return(ret);
 }
 
+/**
+ * xmlParserInputBufferCreateIO:
+ * @ioread:  an I/O read function
+ * @ioclose:  an I/O close function
+ * @ioctx:  an I/O handler
+ * @enc:  the charset encoding if known
+ *
+ * Create a buffered parser input for the progressive parsing for the input
+ * from a file descriptor
+ *
+ * Returns the new parser input or NULL
+ */
+xmlParserInputBufferPtr
+xmlParserInputBufferCreateIO(xmlInputReadCallback   ioread,
+	 xmlInputCloseCallback  ioclose, void *ioctx, xmlCharEncoding enc) {
+    xmlParserInputBufferPtr ret;
+
+    if (ioread == NULL) return(NULL);
+
+    ret = xmlAllocParserInputBuffer(enc);
+    if (ret != NULL) {
+        ret->context = (void *) ioctx;
+	ret->readcallback = ioread;
+	ret->closecallback = ioclose;
+    }
+
+    return(ret);
+}
+
 /**
  * xmlParserInputBufferPush:
  * @in:  a buffered parser input