Proposal of JSONPath transformation service

It uses this library : http://code.google.com/p/json-path/ in order to add this new transformation service, as often a javascript file is used to simply transform a json payload, it would be easier to have this directly in rules, items...
could you please remove this rule and add it to samples section of the Wiki as it does not change anything on the demo UI? We try to keep the demo configuration as small as possible.