Merge branch 'maint-1.7.7' into maint-1.7.8

By Thomas Rast
* maint-1.7.7:
  Document the --histogram diff option
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 9f7cba2..ba7cd13 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -52,6 +52,9 @@
 --patience::
 	Generate a diff using the "patience diff" algorithm.
 
+--histogram::
+	Generate a diff using the "histogram diff" algorithm.
+
 --stat[=<width>[,<name-width>[,<count>]]]::
 	Generate a diffstat.  You can override the default
 	output width for 80-column terminal by `--stat=<width>`.