* Set bootloader to stm32-dfu for STM32F303
* Set bootloader to stm32-dfu for STM32F0x2
* Set bootloader to stm32-dfu for STM32F4x1
* Set bootloader to stm32duino for sowbug
* Delete redundant bootloader_defs headers
* Add some missing MCU name comments
* Move APM32 dfu-suffix overrides underneath bootloader
* Remove redundant STM32_BOOTLOADER_ADDRESS defines/rules
* Add: RGB underglow support using SPI to SteamVan and CO60
* Update: Switch to QMK's baclight implementation for CO60 and SteamVan
* Fix: Remove now unnecessary backlighting code from keyboard files