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/matrix.h

@@ -76,6 +76,13 @@ void matrix_power_down(void);
 /* executes code for Quantum */
 void matrix_init_quantum(void);
 void matrix_scan_quantum(void);
+
+void matrix_init_kb(void);
+void matrix_scan_kb(void);
+
+void matrix_init_user(void);
+void matrix_scan_user(void);
+
 #ifdef __cplusplus
 }
 #endif