Backlight abstraction and other changes (#439)

* redoes matrix pins, abstracts backlight code for B5,6,7

* slimming down keyboard stuff, backlight breathing implemented

* don't call backlight init when no pin

* cleans up user/kb/quantum calls, keyboard files

* fix pvc atomic

* replaces CHANNEL with correct var in breathing

* removes .hexs, updates readmes, updates template

* cleans-up clueboards, readmes to lowercase

* updates readme

tmk_core/common/led.h

@@ -34,10 +34,6 @@ extern "C" {
 
 void led_set(uint8_t usb_led);
 
-/* keyboard-specific LED functionality */
-void led_set_kb(uint8_t usb_led);
-
-
 void led_init_ports(void);
 
 #ifdef __cplusplus