Patch 0.21pre5 for 2.4.17

This batch of changes includes cleanups and code rewrites.
The swap_out_fragments() and find_free_swap_buffer() are
much simpler and also more efficient. Some preliminary
tests showed a performance gain due to these
improvements. See details in the notes link below:

Notes
http://sourceforge.net/project/shownotes.php?release_id=48824

Download
http://telia.dl.sourceforge.net/linuxcompressed/patch-comp-cache-2.4.17-0.21pre5.bz2