Freedups.pl patches

Here is a patch for multiple bugs and issues I have run into with the perl version of freedups. The main site is http://www.stearns.org/freedups/. I have emailed the author with no response. Given that Internet email is continually less reliable this does not surprise me. I am posting my patches here in hopes that others will find them useful and that eventually the author of freedups will notice.

I'm still fixing issues and testing but I feel confident to run this on my backups of 4T. The script runs over the new backup each day which can be up to 2T. (I'm using discremental-lite for backups)

The issues I ran into:

• Bug in core perl module File::Compare - added warning
• stat in line 180 may not work - use of $sb->dev in line 181 is not safe
• file is opened read/write at line 205 - changed to read only
• line 205 kills program if file cannot be opened - made more robust
• line 548 has unsafe check for $Fsb->size

To fix the File::Compare problem I grabbed the latest Compare.pm out of the latest version of perl and replaced the one on my system.