Where viable, customizations in the CubeMX code (mostly the USER
CODE sections) are moved to our own files (primarily main.cpp and
board.cpp).
This will minimize code duplication when adding a new, completely
separate instance of the CubeMX files. The USB code still contains a
large amount of customization which is not touched by this commit and
should be refactored separately later on.
The entry point is now in main.cpp (moved from the CubeMX-generated
main.c). This increases control over the boot process while also
improving code organization.
Paul Guenette
Oskar Weigl
Samuel Sadok