Change of key name "value" to "param"

[UlfBj]

The filter JSON expression has two key names, "type" and "value", as shown in the following example. {"type":"timebased", "value":{"period":"500"}} The key name "value" has two issues,

• it is used as key name also for other key-value pairs,
• it is not particularly descriptive in the filter case.

To improve on these issues it is proposed that it is changed to "param", which would example above being changed to {"type":"timebased", "param":{"period":"500"}}

[UlfBj]

parameter instead of param?

[UlfBj]

PR#470 changes value to parameter.

[UlfBj]

Fixed in PR#470