memcached with ccache

Hi,
Back in 2010, there has been some discussion about supporting memcached as
a backend for ccache:
https://lists.samba.org/archive/ccache/2010q4/000686.html


Looks like this thread hasn't result in code, and I did take a few days to
make an attempt at it.

Here is the first working code:
https://github.com/jrosdahl/ccache/pull/30

Very first bench on my laptop is:
self compiling ccache:
200ms with fs
800ms with memcached

I'll make more bench on our cluster in the next few days.

Regards,
Pierre