Version 1.3.1
* Fix button testing so it does not break USB communication

Version 1.3.0
* Add test for buttons
* Clean USB descriptor
* Return firmware_present in Features response
* Don't halt on broken firware, stay in bootloader

Version 1.2.7
* Optimize speed of firmware update

Version 1.2.6
* Show hash of unofficial firmware
* Use stack protector
* Clean USB descriptor

Version 1.2.5
* Initial import of code