[ic] Bugfix for image.tag

[Jon Jensen]

On Tue, 15 Mar 2011, Josh Lavin wrote:

> Here is the "real" bugfix. Thanks to Jon for pointing me in the right 
> direction and helping to expose a flaw in the way I originally fixed the 
> bug. This time, I fixed $siz instead of mistakenly modifying the 
> filename.

Now it seems like you're removing any of those special characters from 
size altogether, not just for the directory name:

$siz =~ s:[^\dx]::g;
$dir .= "/$siz";