APC ATS 7723 templates

[speculatrix]

I found that existing APC templates really didn't work at all well for these automatic transfer switches, so I ended up learning how to do my own.

I've not got all the fixed thresholds working properly, but it's "good enough" for the moment.

If I knew how to scale data sources, I'd have combine graphs, to show mains voltages, mains frequencies, power and current on the one graph, but because the values are so different the graph didn't work so I created separate ones.

Feedback and fixes appreciated.

--edit--
ah! I discovered custom CDEFs courtesy of
http://gregsowell.com/?p=280
so I've been able to scale the current measurement correctly - APC reports max current as "16" but returns the current as x10.