Compatibility fixes

[crees]

Hey,

Using this on FreeBSD and I've removed a couple of Linuxisms (and corrected a little bit too).

• Sed addressing starts at 1, not 0
• The closing brace of a sed function requires a preceding semicolon or newline
• It's nonstandard to use \n in a sed function, much safer to simply concatenate tmpfiles
• I don't think the chown call ever worked correctly unless run as root-- although I've removed it the correct form is user:group not user.group
• stat(1) is incompatible between GNU and BSD so detect which one to use

It's entirely up to you whether you accept these or just leave mine as a BSD-compatible fork :)

Thanks,

Chris