Value formatter

The Value formatter presents results of database queries as a single value.

To calculate the single value to be returned, it sums the values of all dimensions.

The Value formatter respects the following API &options=:

option	supported	description
`percent`	yes	to replace all values with their percentage over the row total
`abs`	yes	to turn all values positive, before using them
`min2max`	yes	to return the delta from the minimum value to the maximum value (across dimensions)

The Value formatter is not exposed by the API by itself. Instead it is used by the ssv formatter and health monitoring queries.