Prep for a 1.2.4 release candidate

[dormando]

> 
> I spent some time adding a few tests and documenting the CAS and
> append commands in protocol.txt
> 
> Please have a look and let me know if this looks like a viable
> 1.2.4...
> 
> Thanks,
> Paul
> 

There're a couple small patches in the last few days.. The one for 
memcached-tool and the freebsd unix domain sockets. Doesn't matter who 
tests/merges them, but I'm low on time today.

Brian Aker's also been finding some things:

http://tangent.org/552/libmemcached.html

... Suggests using memslap from here to wring out some bugs.

Finally, I'd like to recommend at least one -rc release on this guy, 
which probably just means rolling a tarball and linking it on the list. 
I fear folks who don't rigorously test new versions of memcached getting 
in trouble with this release, and I'd like more time for some of us to 
run Brian's tests and make sure they pass on more platforms.

Btw, sorry for borking part of the clients page.

Thoughts?
-Dormando