Rockbox

This is my first stab at converting buildzip.pl to use native perl functions, rather than calling external apps (causing a pretty hefty slowdown on cygwin). So far, I've simply gone for the low-hanging fruit - simple cp and mv operations.

A recursive delete function should be fairly simple (to replace "rm -rf").

The next step is probably to write a sort of "find" implementation that takes a search expression and a callback function or something like that. It doesn't need to be a full find replacement of course. Just enough to do what buildzip needs (find and copy, I believe).

This will need a fair bit of testing of course, since we don't want the zips to be broken.