Prototype example of a debug box

New features

• The example now features a prototype implementation of a debug box, that handles debug events for uVisor as specified by the uVisor debug box driver.
• If the user does not press the main button, a timeout does that automatically, triggering the expected access fault.

Bug fixes

• Improved checks on uninitialized box contexts. A race condition was able to produce a false positive (the challenge string was mistakenly marked as matching the box secret).
• The on/off logic for the STM32F429-DISCO board was flipped.

Beta OOB Testing release 1

beta-oob-1

Update module names for release.