Modify pg_dump so that the preferred dump order is by name within

Modify pg_dump so that the preferred dump order is by name within
object types, rather than by OID.  This should help ensure consistent
dump output from databases that are logically the same but have different
histories, per recent discussion about 'diffing' databases.  The patch
is bulky because of renaming of fields, but not very complicated.
Also, do some tweaking to cause BLOB restoration to be done in a better
order, and clean up pg_restore's textual output to exactly match pg_dump.