[Twisted-web] nevow.i18n bugfix and feature need review and commit

Hi. The patches attached to these two bugs need a review and someone to commit -- I don't have access to my normal work environment right now. They do two things: - number formatting: _('localization with number %d and floats %f') % (42, 3.141) - support proper pluralization: ungettext('%d dog', '%d dogs', count) % count http://divmod.org/users/roundup.twistd/nevow/issue212 http://divmod.org/users/roundup.twistd/nevow/issue213