Compare live values to stored values.

Develop a way to quantify difference of live values and stored values as one number.

1. The measure of difference should be zero if all live parameters are same as corresponding stored parameter.
2. The measure should scale reasonably with number of parameters.
3. All timing parameters and beam parameters should be accounted for.
4. For cavities only amplitude and phase should count.
5. If there is no stored value for particular parameter (or cavity is absent) it shouldn't be considered.