Document new v7/v8 features; .doc = .txt


git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@252 632fc199-4ca6-4c93-a231-07263d6284db
diff --git a/djpeg.c b/djpeg.c
index 3f261f1..466973f 100644
--- a/djpeg.c
+++ b/djpeg.c
@@ -460,7 +460,7 @@
    * APP12 is used by some digital camera makers for textual info,
    * so we provide the ability to display it as text.
    * If you like, additional APPn marker types can be selected for display,
-   * but don't try to override APP0 or APP14 this way (see libjpeg.doc).
+   * but don't try to override APP0 or APP14 this way (see libjpeg.txt).
    */
   jpeg_set_marker_processor(&cinfo, JPEG_COM, print_text_marker);
   jpeg_set_marker_processor(&cinfo, JPEG_APP0+12, print_text_marker);