[bug-myserver] optimize file cache

[Daniele Perrone]

And just another email for you,
Now I don't have the code here but I think that the way we use to
cache files isn't so good. I understood that myserver at each request,
if a file is not in memory and the cache limits are reached, load it
in memory and then send it to the client. Then there are lucky
clients, that find file they need in the cache, and unlucky clients,
that have to wait for the loading of file in the memory first.
What do you think if we use a statistic approach to load files in to
the memory? Something like, if "file1" is requested at time 0, then at
time 1 maybe  "file2" will be request (using statistical information
we know this), therefor we can just load "file2" at time 0 after
responding to the request.

I hope the idea is clear, I know, ti's just in an emobryonic state,
but I think can be a good improvment in myserver performance.
-- 
Perrone Daniele