Removed oldest v1 style of firmware signature and presence checks.
Added debug helpers for T1 signatures.
Support for v2 and v3 signatures, but can only update FW to v3-style signed.
Support for debugging T1 signatures.
Scripts and README for debugging v2/v3 FW signing scheme.
Firmware in GetFeatures counts only v3 signatures as signed.
Add documentation and comments about signing schemes like a sane person
