Make debug http server more verbose
Make debug http server more verbose

Add some statistics about the number of currently running children
processing request executors and measure time needed to establish
the connection and request execution time.

Signed-off-by: Viktor Bachraty <a13ea37fcfcda126dc54f94389ded93f402eee93@google.com>
Reviewed-by: Brian Foley <a00e555871a6a538e97f8c44307104c884f8e869@google.com>

yiannist/ganeti,ganeti/ganeti,mbakke/ganeti,leshchevds/ganeti,andir/ganeti,ganeti/ganeti,leshchevds/ganeti,onponomarev/ganeti,ganeti/ganeti,mbakke/ganeti,andir/ganeti,leshchevds/ganeti,onponomarev/ganeti,andir/ganeti,yiannist/ganeti,yiannist/ganeti,mbakke/ganeti