fix find-translation-files bug

the lastest downloaded Release and Index files located in skel directory
but not the mirror directory.
Merge pull request #28 from selaselah/master

fix find-translation-files bug
Merge pull request #31 from EifX/master

Added Proxy support
Also mirror xz compressed files (fixes #25).
Set default use_proxy and http_proxy variables.
Run perltidy.
Release 0.5.1
Correct version number