Handle BlueZ 5.x play/pause evdev scancodes

BlueZ 5.x emits [`KEY_PLAYCD`](http://git.kernel.org/cgit/bluetooth/bluez.git/tree/profiles/audio/avctp.c#n266) (kernel: `0xC8`, SDL: `0xD0`) and [`KEY_PAUSECD`](http://git.kernel.org/cgit/bluetooth/bluez.git/tree/profiles/audio/avctp.c#n267) (kernel: `0xC9`, SDL: `0xD1`) evdev key press events for relevant AVRCP button presses instead of `KEY_PLAYPAUSE` (kernel: `0xA4`, SDL: `0xAC`) recognized by XBMC. Thus, two additional SDL scancodes should be mapped to the `XBMCK_MEDIA_PLAY_PAUSE` keysym.

I have successfully tested this pull request with a Dell BH200 headset used with Linux 3.16.5, XBMC 12.2, BlueZ 5.21 and SDL 1.2.15.