Use real firmware file size in the VirtualFAT layer, clean up FAT12 chain update function.

git-svn-id: http://lufa-lib.googlecode.com/svn/trunk@2618 d5102386-fcda-11dd-9fdb-3debd5008f28
Remove debug code from the incomplete Mass Storage class bootloader, rename main source files.

git-svn-id: http://lufa-lib.googlecode.com/svn/trunk@2619 d5102386-fcda-11dd-9fdb-3debd5008f28
Make the VirtualFAT firmware file read from device flash when opened by the host in the incomplete Mass Storage class bootloader.

git-svn-id: http://lufa-lib.googlecode.com/svn/trunk@2620 d5102386-fcda-11dd-9fdb-3debd5008f28