smart indentation for SQL files

[Alex Harsanyi <alexharsanyi@gmail.com>]

Hello,

About 10 years ago I had to edit many SQL files and the sql-mode that shipped
with GNU Emacs did not provide any smart indentation.  At the time, I wrote a
small indentation package, which I used for several months but never released
publicly.

Shortly after, I changed jobs and didn't have to look at SQL files again until
recently. I noticed that the SQL indentation support is still missing from
Emacs and to my surprise my old code worked just fine.

I cleaned up the old code a bit, added suport for indenting WITH statements
and uploaded it to Github at:

    https://github.com/alex-hhh/emacs-sql-indent

The code is similar to cc-mode, in that it separates the "parsing" of the SQL
code from the indentation and the indentation rules can be modified by the
user to conform to local indentaiton guidelines or preferences.

I think this code would be a nice addition to sql.el.

Best Regards,
Alex.