[Fedora-spins] liveusb RFE

As requested, my ticket for the liveusb RFE is: https://fedorahosted.org/liveusb-creator/ticket/642 This was prompted by not being able to easily be able to have large (> 4 GB) images on a usb drive where the extra space was usable by windows. liveusb can't boot off of ntfs (and I am pretty sure the current script won't let you use ext4 even though it should work) and none of the fat varients can have files larger than 4GB. I could use multiple partitions, but it is a pain to have to squeeze do the ext3 partition to not waste space. Since I am under a time limit (for some Christmas gifts), I wasn't going to futz with livecd-iso-to-disk much to try to get this to work right now. Probably I'll look at doing something with it later after some of my other projects are done.