Fixed bootloaders not disabling global interrupts during erase and write operations (thanks to Zoltan).

Add Leonardo compatibility to most bootloaders, run user application if BOOTRST fuse is set and the last reset cause was not the /RESET pin.

Shrink the size of the Printer class bootloader by refactoring the page flush code into a static function.

Tighten up Printer bootloader implementation; fold the IsHEX() function logic into HexToDecimal() and remove redundant state machine state logic to save space in the compiled binary.

Update the Printer class bootloader to use the new Printer Device Class driver, rather than implementing the Printer USB class manually.

Automatically exit the printer class bootloader and start the application when the end of the HEX file is reached (thanks to Hans Schou).

Fixed race condition in the DFU class bootloader causing failed device reprogramming in some circumstances (thanks to Luis Mendes).

Add documentation to the incomplete Mass Storage class bootloader, update the virtual FAT file entry so that the bootloader section is omitted (not user readable/writable). Fix some minor documentation errors in the Printer class bootloader.

Use a temporary variable for the Printer bootloader HEX parser when combining the current and previous data tokens to form a data word, to simplify the code.