Change SQL commands embedded in the initdb script from the style

Change SQL commands embedded in the initdb script from the style
	echo "command" | postgres
to the style
	postgres <<EOF
		command
	EOF
This makes the script more legible (IMHO anyway) by reducing the need
to escape quotes, and allows us to execute successive SQL commands in
a single standalone-backend run, rather than needing to start a new
standalone backend for each command.  With all the CREATE VIEWs that
are getting done now, this makes for a rather substantial reduction
in the runtime of initdb.  (Some of us do initdb often enough to care
how long it runs ;-).)