Merge branch 'jc/color-diff-doc' into maint-1.8.1

The "--color=<when>" argument to the commands in the diff family
was described poorly.

* jc/color-diff-doc:
diff-options: unconfuse description of --color

diff --combined Documentation/diff-options.txt
index 39f2c5074c1ac370976bce36cbceb1a676064cfe,d33f77a05e879905d2d2e3415dd58d68dc17dc18..bbfe8f8f35316462f02864722fdc3c253a16cd01
--- 1/Documentation/diff-options.txt
--- 2/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@@ -170,13 -170,12 +170,13 @@@ any of those replacements occurred
        the commits in the range like linkgit:git-submodule[1] `summary` does.
        Omitting the `--submodule` option or specifying `--submodule=short`,
        uses the 'short' format. This format just shows the names of the commits
 -      at the beginning and end of the range.
 +      at the beginning and end of the range.  Can be tweaked via the
 +      `diff.submodule` configuration variable.
  
  --color[=<when>]::
        Show colored diff.
-       The value must be `always` (the default for `<when>`), `never`, or `auto`.
-       The default value is `never`.
+       `--color` (i.e. without '=<when>') is the same as `--color=always`.
+       '<when>' can be one of `always`, `never`, or `auto`.
  ifdef::git-diff[]
        It can be changed by the `color.ui` and `color.diff`
        configuration settings.
@@@ -309,11 -308,7 +309,11 @@@ endif::git-log[
        index (i.e. amount of addition/deletions compared to the
        file's size). For example, `-M90%` means git should consider a
        delete/add pair to be a rename if more than 90% of the file
 -      hasn't changed.
 +      hasn't changed.  Without a `%` sign, the number is to be read as
 +      a fraction, with a decimal point before it.  I.e., `-M5` becomes
 +      0.5, and is thus the same as `-M50%`.  Similarly, `-M05` is
 +      the same as `-M5%`.  To limit detection to exact renames, use
 +      `-M100%`.
  
  -C[<n>]::
  --find-copies[=<n>]::