A Modbus reader can be added with its own alarm signals

A Modbus reader can now be added as a data logger with its own alarm signals. Each signal has a level, a mode, and a minimum duration before it raises an alarm, and the plant's "Alarm system" page shows its state and its history.

• When a Modbus reader loses connection to its device, an event opens.
• Signals are added by hand, pasted as a list, or learned from the device.
• Deleting the data logger removes its alarm system once it has no signals left.
• The notifications carry each signal's name and its type.
• The date range on the "Alarm system" page can now be chosen freely for all signals at once.