extra time diff check to eliminate possibility for unnecessary frame fetching
Merge branch 'queue_optimization'
Parameter values bulk read

When the parameter page is read the server creates a thread
that reads parameter values to a queue stored in the session.
The fuction getparams empty the queue, it should be called
until all values are read. The queue is deleted when emptied.
Works better with GDBus bindings, could segfault with python-dbus when reloading parameter view several times before it had finished loading
Adding support for bulk parameter reading
Fixing a bug that would cause the refresh timer to start even when autorefresh was off