There is a strictly correct answer and a practical answer.
The strictly correct answer is to leave out the commas (as @DanBron explained in his comment) and add this after the quote:
[punctuation as in original]
This follows a similar convention when your source material includes either emphasis (italic text) or misspellings.
HOWEVER, this strictly correct approach does no service for the reader, in my opinion. Just what punctuation was or is out of place in the original?
The practical answer is to add the commas as your editor recommends. It doesn't change the meaning of the quote at all, and thus does not harm to the source or its author. After the quote, you could add...
...to be totally honest, but what does the reader gain by this? Nothing, in my opinion.
What would you do in this case?: The source material omitted the period at the end of the first of two sentences. If this is edited material and not from some informal source like on-line chat session, then we would conclude that omission of the period was a typographical error. We would do our own readers a service by adding the period back in.