Muon Kicker: Monitor Kicker Stability

As a muon scientist, I need the Kicker stability to monitored, so that I can be alerted if it is not behaving in a stable manner.

#### Acceptance Criteria
1. I can view whether the Kicker is currently stable or not
* A green (stable)/red (unstable) LED is sufficient.
1. I receive an alarm when the Kicker becomes unstable (the alarm should be a Nagios alarm)
* the instablity should be logged as a MAJOR event
1. I can view whether the Kicker has fired recently:
* fired recently (LED is unlit); not fired recently (LED is lit, red)

#### Notes
1. required by #3071
1. The Kicker PSU is controlled by a National Instruments DAQ device.
1. These [criteria](http://www.facilities.rl.ac.uk/isis/computing/ICPdiscussions/Muon%20FE/Muon%20FE%20Kicker%20Criteria.docx) define when the:
1. the Kicker is considered to be stable,
1. the Kicker is considered to have fired.
1. If the Kicker PSU is switched off, alarms should not be generated.