pretty print viewdefs

The tiny patch attached fixes a long-standing peeve of mine (and at
least one of my clients'), namely that the target list printed in
viewdefs are unreadable.

example output now looks like this:

regression=# select pg_get_viewdef('shoe',true);
pg_get_viewdef
-----------------------------------------------
SELECT
sh.shoename,
sh.sh_avail,
sh.slcolor,
sh.slminlen,
sh.slminlen * un.un_fact AS slminlen_cm,
sh.slmaxlen,
sh.slmaxlen * un.un_fact AS slmaxlen_cm,
sh.slunit
FROM shoe_data sh, unit un
WHERE sh.slunit = un.un_name;

Is there any objection?

cheers

andrew