RTL text and the new `indent-rigidly'

[Chong Yidong]

The new behavior of indent-rigidly in Emacs 24.4 seems to be
inconsistent with our existing handling of right-to-left text.

In right-to-left text, the left and right arrow keys move in the visual
sense (whereas C-f and C-b move in the logical sense).  However, when
you call `C-x TAB' (indent-rigidly) to activate the new transient mode
for adjusting indentation interactively, the left key indents the text
rightward, and the right key indents the text leftward.

I think these subcommands should check current-bidi-paragraph-direction,
and indent in the visual sense.  Any objections?