Teach --text option to diff

Add new item text to struct diff_options.
If set then do not try to detect binary files.

Signed-off-by: Stephan Feder <sf@b-i-t.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/diff.h b/diff.h
index d557394..f80f646 100644
--- a/diff.h
+++ b/diff.h
@@ -42,6 +42,7 @@
 	unsigned recursive:1,
 		 tree_in_recursive:1,
 		 binary:1,
+		 text:1,
 		 full_index:1,
 		 silent_on_remove:1,
 		 find_copies_harder:1,