Discuss clang-format options.

This isn't meant to be merged, but rather, be a discussion about which
options people want to use. I've added comments next to each formatting
option that clang-format supports and that we specify. Many of them are
fairly obvious choices and some of the settings I'm ignoring for now,
either for future discussion or because they are for fine tuning later and
not important at the moment.

For things I want to call out as potentially contentious, I'll have the
comments start with **'s.
Well the worst case of consecutive closing braces is actually in ircutil.cpp so isn't even our code:
```
            if (pos > 0 && href.endsWith(QLatin1Char(')')) 
                && (processed.at(pos-1) == QLatin1Char('(') 
                || !href.contains(QLatin1Char('('))))
            {
                append.prepend(href.right(1));
                href.chop(1);
            }
```
Typically the worst I'm seeing in our own work is the connect() method to wire up SIGNALs and SLOTs together, they tend to be very long lines anyhow and getting the braces right if editing them, especially toward the SLOT end.  We could break the longer ones up I suppose (well that might now happen automagically with any beautifier)... but for someone who's system is not the most powerful Qt Creator gets realllllyyyyyy ssslllllooooowwww in the braces/parentheses highlighting, especially if there are more than a few "Issues" being highlighted or for a big file (TLuaInterpreter.cpp f'instance).