* Remove unnecessary IS_COMMAND definition in clueboard/66/rev4
* Replace keyboard_report->mods with get_mods() in IS_COMMAND definitions
* Update docs to use get_mods() instead of keyboard_report->mods
* Replace keyboard_report->mods with get_mods() in tmk_core/protocol/usb_hid/test
For some reason, this occurrence used KB_LSHIFT and KB_RSHIFT, which don't exist
* Replace keyboard_report->mods with get_mods() in Massdrop keyboards (as per @patrickmt)
* handwired/promethium: refactor
- config.h files
- updated to use #pragma once
- removed redundant config.h includes
- layout macro moved from config.h to promethium.h
- layout macro renamed from KEYMAP_CUSTOM to LAYOUT
* handwired/promethium: Configurator support
