StringArray::addTokens does not remove quotes

I extended the addTokens method so it can remove the quotes you specify which I find quite useful.

It's much better practice to prefer utility functions that aren't tightly-coupled to existing code.. e.g. you could have just written a free function, which would do the job very cleanly:

static void addTokensRemovingQuotes (StringArray& target, StringRef text, StringRef breakCharacters, StringRef quoteCharacters)
    target.addTokens (text, breakCharacters, quoteCharacters);

    for (String& s : target)
        s = s.unquoted();