Refactor Bluetooth Handling

Refactored Bluetooth support to make adding new Bluetooth modules
easier in the future.

* Remove `OUT_BLE` key from QMK's keymap. `OUT_BT` is all we need now
as there's no difference anymore.
* Made BLUETOOTH_ENABLE build option legacy as not to break existing
keymaps (Falls back to existing EZ Key support if on)
* Removed `ADAFRUIT_BLE_ENABLE` build option
* Created new build option `BLUETOOTH` with module option (Currently
`AdafruitEZKey` & `AdafruitBLE`)
* Moved all LUFA bluetooth key/mouse events under `BLUETOOTH_ENABLE`
ifdef with selected modules output.

tmk_core/protocol/lufa/adafruit_ble.h

@@ -3,7 +3,7 @@
  * Supports the Adafruit BLE board built around the nRF51822 chip.
  */
 #pragma once
-#ifdef ADAFRUIT_BLE_ENABLE
+#ifdef MODULE_ADAFRUIT_BLE
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
@@ -57,4 +57,4 @@ extern bool adafruit_ble_set_power_level(int8_t level);
 }
 #endif
 
-#endif // ADAFRUIT_BLE_ENABLE
+#endif // MODULE_ADAFRUIT_BLE