DDG: make output format and separator configurable

[Pulecz]

Currently in lots of search outputs the link to the search result is only after the description of the link which often can be after first 512 characters (the IRC message limit). So if the user want's to get to the link fast they often have to write more command.

To put the link first it's as simple to switch the order here https://github.com/progval/Limnoria/blob/master/plugins/DDG/plugin.py#L164
strings.append(format("%u - %s %s", r[2], ircutils.bold(r[0]), r[1]))

Personally I am not a fan of "," as a separator so I edited it to red bold "|"

separator = ircutils.bold(ircutils.mircColor(" | ", "red"))
irc.reply(separator.join(strings), prefixNick=True)

However the preference can vary a lot, so it would be best to make it configurable somehow, rather than forcing new defaults.