Merge branch 'jc/maint-grep-untracked-exclude' into jc/grep-untracked-exclude

* jc/maint-grep-untracked-exclude:
  grep: teach --untracked and --exclude-standard options
  grep --no-index: don't use git standard exclusions
  grep: do not use --index in the short usage output

Conflicts:
	Documentation/git-grep.txt
	builtin/grep.c

Documentation/git-grep.txt

@@ -23,7 +23,7 @@ SYNOPSIS
 	   [-A <post-context>] [-B <pre-context>] [-C <context>]
 	   [-f <file>] [-e] <pattern>
 	   [--and|--or|--not|(|)|-e <pattern>...]
-	   [--cached | --no-index | <tree>...]
+	   [ [--exclude-standard] [--cached | --no-index | --untracked] | <tree>...]
 	   [--] [<pathspec>...]
 
 DESCRIPTION
@@ -49,7 +49,20 @@ OPTIONS
 	blobs registered in the index file.
 
 --no-index::
-	Search files in the current directory, not just those tracked by git.
+	Search files in the current directory that is not managed by git.
+
+--untracked::
+	In addition to searching in the tracked files in the working
+	tree, search also in untracked files.
+
+--no-exclude-standard::
+	Also search in ignored files by not honoring the `.gitignore`
+	mechanism. Only useful with `--untracked`.
+
+--exclude-standard::
+	Do not pay attention to ignored files specified via the	`.gitignore`
+	mechanism.  Only useful when searching files in the current directory
+	with `--no-index`.
 
 -a::
 --text::