Don't require authorization if API key is empty
[apiexamples] Make'em compatible with Python3
Add script for testing Python API
Fix incorrect information in CHANGELOG

--set-profile is right name of command line option for switching
profiles.
[firmware] Update files from LUFA project

Now we use latest from git/master, commit
250feb29cfb4057824fbc4207cf87a4a1f1e8ebc