Cacheboy-HEAD updates

I've finished cleaning up the bits of the IPv6 work from CACHEBOY_HEAD - it should be just a slightly better structured Squid-2.HEAD / Cacheboy-1.5.

Right now I'm pulling out as much of the HTTP related code from src/ into libhttp/ before the 1.6 release. I'm hoping to glue together bits and pieces of the HTTP code into a very lightweight (for Squid) HTTP server implementation which can be used to test out various things like thread safe-ness. Of course, properly testing thread-safeness in production relies on a lot of the other code being thread-safe, like the comm code, the event registration code, the memory allocation code, the debugging and logging code ... aiee, etc. Oh well, I said I wanted to..

I'm also going through and adding some headerDoc comments to various library files. headerDoc (from apple) is actually rather nice. It lacks -one- function - the ability to merge multiple files together (say, libsqinet/sqinet.[ch]) into one "module" for documentation. I may look at doing that in some of my spare time.

Reverting IPv6 for now; moving forward with structural changes

I've been working on the IPv6 support in Cacheboy for a couple months now and I've come to the conclusion that I'm not getting anywhere near as far along the development path as I wanted to be.

So I've taken a rather drastic step - I've branched off CACHEBOY_HEAD from the last point along the main codebase where the non-intrusive IPv6 changes had occured and I'm going to pursue Cacheboy-1.6 development from that.

The primary short-term goal with Cacheboy was to restructure the codebase in such a way as to make further development much, much simpler. I sort of lost track with the IPv6 development stuff and I rushed it in when the codebase obviously wasn't ready.

So, the IPv6 changes will stay in the CACHEBOY_PRE branch for now; development will continue in CACHEBOY_HEAD. I'll continue the restructuring work and stability work towards a Cacheboy-1.6 release come January 1. I'll then look at merging over the IPv6 infrastructure work into CACHEBOY_HEAD far before I merge in the client and server related code - specifically, completing the DNS updates, the ipcache/fqdncache updates, port over the IPv6 SNMP changes from Squid-3, and look at modularising the ACL code in preparation for IPv6'ifying that. The goal is less to IPv6-ify Cacheboy; its more to tidy up the code to the point where IPv6 becomes trivial.