More FileRequester Fixes

Thanks to Quirky’s patch, the FileRequester class now works correctly with devKitARM r24. I’ve tested it on the real hardware (none of the emulators seem to have working FAT emulation at the moment, which is odd as I’m sure I’ve used it before) and the latest version of libfat is considerably faster than the old version. In the “filerequester” example, the FAT system initialises in about a second, compared with about five seconds for the previous version.

Whilst testing that, I noticed that the requester wasn’t highlighting options correctly any more. Traced this to a bug in the ListBox class - the selection routine wasn’t redrawing the gadget. This only became an issue since I fixed the bug that prevented single selection mode from being activated.