This patch introduces dynamic timer intervals: we slow down the refresh
rate when there in no much activity but we get back to a fast refresh
rate when the activity resume.

Please note that qemu_timer_expired is not an inline function any more
because I needed to call it from vnc.c however I don't think this change
should have any serious consequence.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Message-Id: