[SQLObject] Transaction fixes

[Ian B. <ia...@co...>]

Made a bunch of fixes to how transactions work in CVS.  Maybe they are 
now functional even, if not perfect.

I'm going to be keeping tarballs of CVS that are updated as I do stuff, 
so that interested parties don't have to wait for anon CVS to update 
(or be unsure whether they are working on an updated copy).  This will 
generally be in:
   http://colorstudy.com/ianb/SQLObject-cvs.tar.bz2

To flesh transaction support out a bit better, I'll soon be adding the 
ability to expire an instance -- when the instance is next accessed it 
will update itself from the database.  So on a rollback every object in 
the transaction will be expired.  I suppose on a commit every object 
outside of the transaction that is also present in the transaction 
should be expired.  But I'll have to think about that -- worries me to 
change objects other threads may be in the middle of working with.  
Anyway, you won't have to use _cacheValues=False with transactions 
then.  It will also expedite a .sync() method (or something along those 
lines).

   Ian