Add setImageMode using Enum type as input nowait
add a handy method to return a PV value monitor of a channel so any
MonitorListener can be attacthed to later, this way GDA object can help
to manage IOC server resources on connection and disconnection
add support for EPICS piezo motor which updating its RBV all the time
even it had stopped. This class should be used if you want to avoid jam
up the corba event system and make scan more responsive. In the past we
nomarlly set this to PULL rather than LISTEN mode in SWING