[ccache] ccache 2.2 and distcc 1.2.2 works

[Martin Pool]

ccache 2.2 and distcc 1.2.2 seem to fix the problem of false misses
when these programs are used together.  When I build samba's 3_0
branch with CC='ccache distcc gcc-3.2' then almost every file gets a
cache hit.

-- 
Martin