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

keyboards/planck/keymaps/ab/readme.md

@@ -0,0 +1,18 @@
+# Practical keymap for Planck Ortholinear 40% Mechanical Keyboard
+A practical keymap that emulates standard QWERTY keyboard for Planck. Once you get comfortable with this keymap, you may fork and customize it for your own needs. 
+
+![Layout](keyboard-layout.png "Practical Keymap")
+![Photo](keyboard-photo.jpg "Planck Keyboard")
+
+* Online keyboard layout editor: http://goo.gl/mlLAFZ
+
+# Programming Instructions:
+Enter into programming mode and run the following command.
+```
+$ sudo KEYMAP=ab make dfu
+```
+# Notes
+* Simultaneous RAISE+LOWER enters CUSTOM layer. You may add your own macros and custom keys here.
+* RAISE and LOWER also acts as PgUp and PgDn when tapped.
+* [CapsLock] also acts as [Ctrl] key when you press and hold. It is convenient for GNU Emacs users.
+* Bracket keys are placed in the center of the keyboard for programmer's convenience.