Merge branch 'jn/editor-pager'

* jn/editor-pager:
  Provide a build time default-pager setting
  Provide a build time default-editor setting
  am -i, git-svn: use "git var GIT_PAGER"
  add -i, send-email, svn, p4, etc: use "git var GIT_EDITOR"
  Teach git var about GIT_PAGER
  Teach git var about GIT_EDITOR
  Suppress warnings from "git var -l"
  Do not use VISUAL editor on dumb terminals
  Handle more shell metacharacters in editor names

git-add--interactive.perl

@@ -990,8 +990,7 @@ sub edit_hunk_manually {
 EOF
 	close $fh;
 
-	my $editor = $ENV{GIT_EDITOR} || $repo->config("core.editor")
-		|| $ENV{VISUAL} || $ENV{EDITOR} || "vi";
+	chomp(my $editor = run_cmd_pipe(qw(git var GIT_EDITOR)));
 	system('sh', '-c', $editor.' "$@"', $editor, $hunkfile);
 
 	if ($? != 0) {