Fix broken deadman extra expressions

[nathanielc]

Fixes #718

We need to add tests for this but its not easy until the deadman can have its own clock. I'll create an issue to track this. #754

• Rebased/mergable
• Tests pass
• CHANGELOG.md updated

[gargooza]

Just to confirm, will this fix this error?
<30> Jul 25 18:15:07.106552 -04:00 kapacitord: [aCSE:alert5] 2016/07/25 18:15:07 E! error evaluating expression: Failed to handle 1 argument: name "time" is undefined. Names in scope: emitted

[nathanielc]

Yes.

FWIW the cause of the error was the the LambdaNode itself was being appended to the alert condition instead of the expressions contained in the LambdaNode. Essentially doing this:

|alert()
   .crit(lambda: "emitted" < threshold AND lambda: hour("time") >= 20)

Which is clearly wrong, and confused the evaluation of the crit expression.

[bowdenandrew]

Thanks Nathaniel,

That definitely fixed the bug that I was seeing, I'll work up some more robust samples and if I have any further problems I'll let you know.

Thanks so much for making this code change.

Andrew