add threshold management with CheckThresholdCross processor

[oalam]

USER STORY

As a user, I want to checks that som thresholds are crossed so that I can define some threshold based alerts

        - processor: compute_thresholds
          component: com.hurence.logisland.processor.CheckThresholdCross
          type: processor
          documentation: |
            compute threshold cross from given formulas.
            each dynamic property will return a new record according to the formula definition
            the record name will be set to the property name
            the record time will be set to the current timestamp

            a threshold_cross has the following properties : count, sum, avg, time, duration, value
          configuration:
            cache.client.service: cache
            default.record_type: threshold_cross
            default.el.language: js
            default.ttl: 300000
            tvib1: cache("vib1").value > 10.0;
            tvib2: cache("vib2").value >= 0 && cache("vib2").value < cache("vib1").value;

ACCEPTANCE CRITERIA

1. 1. 1.

DEFINITION OF DONE

• Code builds without warnings (technical task)
• Code unit tested (technical task)
• Code is reviewed by a peer colleague
• Documentation updated (user story)
• Build pushed to demo server (user story)