diffStr ignore white space issues

[brodieG]

Basically arises because it is possible for two elements that are the same two differ in the following way in different objects:

obj: int[1:10] ...
obj   :  int[1:10] ...

This happens because in the second object some name has been made longer and how every other name is space padded to that length, and the colon is added after. Unfortunately since in the first one there is no whitespace at all trimming whitespace is defeated because interior whitespace trimming reduces multiple whitespaces to 1 whitespace, not 0.