Utility to restore backups

Ready for mainline

So as it turns out, you can restore an instance's backup to another instance, i.e., you can load a backup of production into the training instance, but journal files appear to have the path of the database file embedded inside them, so you can't apply production's journals into the training instance. (At least, not easily...) This means we can get rid of a lot of fancy logic trying to detect and handle this case. And -j doesn't need an argument anymore.

Also, since old journal files are timestamped, the default behavior does not need to be "remove existing journals". We just need to shut off journaling and move the current journal file out of the way.

Here's the final usage, as of rev 81, when I proposed merging this into mainline:

Usage: ovrestore [-y] [-q] [-j] [-f] INSTANCE_NAME BACKUP_FILE
   or ovrestore -h

  -y do not ask for confirmation
  -q quiet; suppress status messages
  -j after restoring the backup, apply journal entries
  -f force; kill any processes accessing the database before restore
  -h display this help text

Here's an example of "disaster recovery":

[jon@avgtmint02 ~]$ sudo ovinstanceadd test
[jon@avgtmint02 ~]$ openvista test

TEST>S ^JON=""

TEST>S ^JON(0)="This should be in the backup"

TEST>h
[jon@avgtmint02 ~]$ ovbackup -q test
[jon@avgtmint02 ~]$ openvista test

TEST>S ^JON(1)="This should only be in the journals"

TEST>h
[jon@avgtmint02 ~]$ sudo rm /opt/openvista/test/globals/default.dat
[jon@avgtmint02 ~]$ openvista test

TEST>ZWR ^JON
%GTM-E-DBFILERR, Error with database file /opt/openvista/test/globals/default.dat
%SYSTEM-E-ENO2, No such file or directory

TEST>h
[jon@avgtmint02 ~]$ sudo ovrestore -j test /opt/openvista/test/backups/test-20090416-220704.tar.bz2
Routines and database files in 'test' will be OVERWRITTEN with
the versions in '/opt/openvista/test/backups/test-20090416-220704.tar.bz2'

Are you sure you want to restore this backup to 'test' (yes/no)? yes

Apr 16 22:07:57 - Starting restore of /opt/openvista/test/backups/test-20090416-220704.tar.bz2 to test
Apr 16 22:07:57 - Extracting contents of backup file
Apr 16 22:07:57 - Attempting to acquire exclusive access to database
Apr 16 22:07:57 - Restoring routines
Apr 16 22:07:57 - Restoring database files
Apr 16 22:07:57 - Applying journal entries
Apr 16 22:07:57 - Enabling journaling on new database
Apr 16 22:07:57 - Finished restoring /opt/openvista/test/backups/test-20090416-220704.tar.bz2 to test
[jon@avgtmint02 ~]$ openvista test

TEST>ZWR ^JON
^JON=""
^JON(0)="This should be in the backup"
^JON(1)="This should only be in the journals"

TEST>h