table/index fillfactor control, try 3

This is the 3rd revised fillfactor patch.
Now, AM specific options are stored in pg_class.reloptions as text[].
Also, some bugs are fixed. It passed all regression tests.

Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> An opaque bytea won't do though. What I'd suggest is something real
> close to the format used for GUC parameters in ALTER DATABASE SET and
> ALTER USER SET, ie, pairs of keyword/value strings. This way pg_dump
> doesn't need very much smarts about what the values are that it's
> dumping.

The column format of options is changed from bytea to an array of text,
so re-parsing is needed every time a connection accesses a relation.
I changed to write pre-parsed options into pg_internal.init, but AFAICS,
only system relations are written in it. If we will find the parsing
is slow, it might be good to store options for user relations, too.

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center