This patch prunes raw_node_ref's from RAM so as to achieve a fixed
steady state RAM memory footprint when the number of files is constant. 

The diff is against the eCos repository since thats where all this
started:

http://ecos.sourceware.org/ml/ecos-discuss/2004-07/msg00158.html



Remaining issues to be checked:

- Is the code correct? 
- What performance impact does it have? 

-- 
Øyvind Harboe
http://www.zylin.com