Add new package "xbmc-dev-tools" containing TexturePacker for skinners.

While modifying default skin I realized that you have to use TexturePacker to repack media images.

However to use TexturePacker you have to compile XBMC. While I am fine with this, it did take a long time for what it really needs to be.

I also came across this thread, where a guy wanted to create a skin, but gave up because he couldn't compile XBMC to get TexturePacker.
http://forum.xbmc.org/showthread.php?pid=604845%23pid604845

I believe that if someone wants to create or modify XBMC skin, they don't necessarily need to be able to compile XBMC, and a compiled windows binary seems to be included anyway.

Since TexturePacker is compiled while building XBMC debian package, I though that it might be useful to create a separate package with TexturePacker.

The changes proposed in pull request achieve this with new package "xbmc-dev-tools".