[Dev] No Perl Threads on Mandriva by Default

[Leo Bayer]

The perl install that ships with Mandriva is built without threads 
support.  As a result, I am no longer able to perform any backups due to 
"use" failures.

It appears that it isn't trivial to install perl with threads support. 
(I would have to compile it myself)

Because we use threads to solve a windows issue can we only use threads 
on windows?

- Leo