also use refcounting for eTimers

also use refcounting for eTimers
its now no more possible directly to call new eTimer .. or to embedded
eTimer.
to create a eTimer now eTimer::create must be used... to delete you must
call ->AddRef() after timer creation and ->Release when the timer is no more
needed. Or use ePtr<eTimer> to store the timer reference.. then its enough
to set the ePtr<eTimer> object to 0 when the timer is no more needed