[elephant-devel] fix of ele-postmodern to work with recreate-instance-using-class

[Alex Mizrahi]

the problem was actually quite easy -- pm-btree needs to initialize it's 
transient each time it's created or deserialized. it participates both as 
descendant from "persistent" as pm-btree itself, and as persistent-object in 
form of pm-indexed-btree.

(so pm-btree is quite a good test for a new system)

as we've found out, now initialization of transient slots should be done in 
shared-initialize :after (it's funny, nobody have replied directly to my 
concrete question, but it was mentioned in some 'proposals').

unfortunately original implementation of recreate-instance-using-class 
deprives "persistent" from any kind of initialization, including 
shared-initialize. i believe it's a bug and recreate-instance-using-class 
either should call normal make-instance for everything except 
persistent-object. or, at least, it should call shared-initialize.
(again, this was in my original question but nobody addressed this issues 
directly. is my English that poor so nobody understand me??).

so, fix consists of two parts:
 1. `persistent' gets normal initialization via make-instance (i've already 
posted code), so pm-btree has chance to initialize itself;
 2. initialize-instance :after of pm-btree is changed to shared-initialize 
so it will work for pm-indexed-btree which is persistent-object.

does this make sense according to original design? if it does, i'll send a 
patch.

if part 1 is against the spirit of this recreate thing we can just add 
shared-initialize call in recreate-instance of `persistent'.
i don't see how it will change anything though..

p.s. fixing this was somewhat complicated because it didn't clearly report 
problem that pm-btree is not initialized, but tried to initialize itself in 
erroneous and confusing way in some obsoleted code path. i'm going to delete 
these code pathes, so we won't be confused if something like that happens 
again