FLUID-5512: Fix for compound valueMapper issue, by consolidating deepEq algorithm with the one now implemented in DataBinding. 

This mildly extends the algorithm to count unchanged values as well as changed ones, and implements a new ranking algorithm and option accepted by the valueMapper named "partialMatches" which may appear on an individual option as well as on the valueMapper transform as a whole. Rationalised naming of "transform" to "transformer" as the last argument of a transform
The comment for the parameter "options" needs to be updated to reflect the addition of "unchanged" and what it's for.