[development] access to $node in hook_fillter()

[Moshe Weitzman]

> As far as I can see, _filter only receives a 'stupid' text-chunk, but I cannot 
> beleive that we designed it that stupid and never pass more information to he 
> filters. Its just that I cannot find the wheres, hows and whens.

thats how it works. there have been long debates about this in the past. see 
http://www.acko.net/blog/drupal-filter-formats and http://drupal.org/node/11225

lets be a bit more *positive* and refrain from calling designs 'stupid'.