new feature to perform an automatic stop of a switch when some value reach some conditions. For that some new attributes has been introduced using suffixes to the one with the feature:
- an spectrum *_AutoStop the size of which depends on the value of another auxiliar called *_AutoStop_IntegrationTime,
- an enable of the feature to allow the user to inhibit this feature if needed, called *_AutoStop_Enable,
- statistical attributes *_AutoStop_{Mean,Std} to report information used to take the decission,
- a boolean reporting that the autostopper is acting, *_AutoStop_Triggered,
- scalars with the threshold conditions, *_{Below,Above}_Threshold as configurable limits to trigger this feature.

git-svn-id: https://svn.code.sf.net/p/tango-ds/code/DeviceClasses/AcceleratorComponents/LinacAlba/trunk@18954 3b39871e-fe4b-0410-b5db-e82997f68959