Suppress Pango's bidi, by displaying RTL characters one at a time. I

Suppress Pango's bidi, by displaying RTL characters one at a time. I
hadn't previously noticed, but Pango was helpfully re-reversing text
that PuTTY's own bidi module had already reversed, leading to Arabic
text being wrongly displayed and also total chaos when you move the
cursor over it or try to cut and paste it.

git-svn-id: http://svn.tartarus.org/sgt/putty@9294 cda61777-01e9-0310-a592-d414129be87e