* Better handle LTO_ENABLE
Especially when calling from command line
* Replace LINK_TIME_OPTIMIZATION_ENABLE with LTO_ENABLE
* Remove long for LTO from show_options.mk
* initial commit for froggy 106 key mode
* add mode indicator on OLED
* use #pragma once instead of include guard
* remove unusable codes
* remove audio codes, because helix rev.2 has no audio feature
* use set_single_persistent_default_layer
* remove eeprom update check