- parser.c xmlIO.[ch]: fixed the problem of encoding support

when using in memory parsing. Need some cleanup.
- xmllint.c configure.in: added a --memory flag to test memory
  parsing
Daniel

include/libxml/xmlIO.h

@@ -83,6 +83,9 @@ xmlParserInputBufferPtr
 xmlParserInputBufferPtr
 	xmlParserInputBufferCreateFd		(int fd,
 	                                         xmlCharEncoding enc);
+xmlParserInputBufferPtr
+	xmlParserInputBufferCreateMem		(const char *mem, int size,
+	                                         xmlCharEncoding enc);
 xmlParserInputBufferPtr
 	xmlParserInputBufferCreateIO		(xmlInputReadCallback   ioread,
 						 xmlInputCloseCallback  ioclose,