Fix the DiffMatchPatch word diff unit tests marked as skip

[evandrocoan]

The word diff marked as skip were introduced on commit:

1. d2c5d43 - Set the default TestingUtilities diffMode to 0 characters because

The diff for theses tests case work fine if using diffMode=0 as characters. The problems noted rises when using the words and lines mode. However, the characters mode itself is not good on some situations because produce too much noise.

Then, perhaps create a automated way of detection which mode should be the best and automatically selection whether it will be character, word or line mode.