Urgent:

* Document new DEFINE directive in config file and manpath(5)

In progress:

* get pre-processors from file at mandb time and store in the db.
* store .so link in the db.
* reduce wasted/duplicated text stored within the databases.
  10-20% database size reduction so far.
* execute pipelines inline rather than using the shell.

In need of attention:

* clear up the use of troff and/or groff
* complete configuration file redesign to allow better dynamic determination 
  of programs/paths/extensions etc.
* use zlib for gzipped pages rather than forking gzip.
* look at work done by SuSE and Andries.
