Attempt at a hot backup integration [patch](Scanned for viruses: Notes Admin)

[vb...@siuh.edu]

Attached please find my attempt at incorporating hot-backup.py 
functionality into subversion.  This patch supposed to replace the steps 2 
through 4 of hot-backup.py.

There is one noticeable difference between hot-backup.py and this patch is 
in the way they copy db folder.  Instead of copying entire repository and 
then recopying logs, this patch copies the repository with exception of db 
folder. Then on svn_fs_* level, there is a function makes a copy of every 
database file and then all log files.  This way logs will not need to be 
copied twice.  However, one downside of this is that if someone puts their 
own files into the db folder they will not be backed up.  However, I do 
not think this will be an issue.

The only one part of this patch I am a little concerned about is my use of 
__os_free function that db_archive application uses which is specified in 
<db_int.h>.If anyone is familiar with that function I would really 
appreciate any information, before I go bother people on BDB lists.



Sincerely,
Vladimir Berezniker