Cacheboy-1.3 (.1) released; short-term future

I've just merged the latest Squid-2.HEAD changes into Cacheboy and released 1.3.1.

1.3 and 1.3.1 fix the Vary related issues which affects hit rates.

1.3.1 fixes the SNMP counter bugs.

This ends the first set of mostly non-intrusive changes which have been made to the codebase. The next area of work will be pulling out the rest of the event/communications/signal code from src/ and into libiapp/ so I can begin treating "Squid" as a client of "libiapp" - ie, the libiapp code handles event, fd, communication and event scheduling (disk stuff is still in src/ for now) making callbacks into the Squid application. I can then begin writing a few test applications to give the core and support libraries a good thrashing.

I'll start planning out threading and ipv6 support in the libraries themselves with the minimum amount of Squid changes required to continue functioning (but still staying in IPv4/non-threaded land.) The plan is to take something like a minimalistic TCP proxy thats been fully debugged and use it as the basis for testing out potential IPv6 and threading related changes, seperate from the rest of the application.

My tentative aim is to run the current "Squid" application in just one thread but have the support libraries support threading (either by explicitly supporting concurrency or being labelled as "not locking" and thus callers must guarantee nothing quirky will happen.) The three areas that strike me as being problematic right now are the shared fd/comm state (fd_table[]), the statistics being kept all over the place and the memory allocator routines. (I'll write up the malloc stuff in a different post.)