[PATCH] Reword -M, when in `git log`s documention, to suggest --follow

[Alex Vandiver <alex@chmrr.net>]

The documentation for `git log` is sadly misleading when it comes
to tracking renames.  By far the most common option that users
new to git want is the ability to view the history of a file
across renames.  Unfortunately, `git log --help` shows:

    NAME
           git-log - Show commit logs
    [...]
    OPTIONS
    [...]
           -M
               Detect renames.

...and most users stop reading there.  Unfortunately, what
they're generally looking for comes significantly later:

    [...]
           --follow
               Continue listing the history of a file beyond renames.

Signed-off-by: Alex Vandiver <alex@chmrr.net>
---
 Documentation/diff-options.txt |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 8707d0e..bcbad88 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -175,7 +175,13 @@ endif::git-format-patch[]
 	Break complete rewrite changes into pairs of delete and create.
 
 -M::
+ifdef::git-log[]
+	Show renames in diff output.  See `--follow` to track history
+	across renames.
+endif::git-log[]
+ifndef::git-log[]
 	Detect renames.
+endif::git-log[]
 
 -C::
 	Detect copies as well as renames.  See also `--find-copies-harder`.
-- 
1.6.6.rc0.363.g69d13.dirty