[BOARD/PACKAGE] add FFMPEG to record&play /dev/fb0 + alsa capture (#48)

* [PACKAGE] downgrade FFMPEG(add) & X264
- use ffmpeg-3.1 thus downgrade ver. to working SDL1.2
- downgrade x264 to be inline with former ffmpeg
- uncomment FFSERVER build instructions (it is available in 3.1 version)

* [BOARD] 
- add `ffplay` & `ffmpeg` apps to record&play
- add `arecord` script for AUDIO capture (use alsaloop workaround)
- update appLinks with "params=&" for bg launch
- use `pkill` instead 'killall` for scripts (warning: it also checks for bash running under the same name)
- use FFPROBE to detect media format in `ffplay`
- for X264  use sources.buildroot.net (code.videolan.org src only works with git method)
- rm redundant usb Applink
- add 0003-ffplay-custom-sdlk.patch (to make hotkeys usable in miyoo)

configs/miyoo_uclibc_defconfig

@@ -35,6 +35,13 @@ BR2_PACKAGE_ALSA_UTILS_APLAY=y
 BR2_PACKAGE_ALSA_UTILS_SPEAKER_TEST=y
 BR2_PACKAGE_ESPEAK=y
 BR2_PACKAGE_ESPEAK_AUDIO_BACKEND_ALSA=y
+BR2_PACKAGE_FFMPEG=y
+BR2_PACKAGE_FFMPEG_GPL=y
+BR2_PACKAGE_FFMPEG_NONFREE=y
+BR2_PACKAGE_FFMPEG_FFPLAY=y
+BR2_PACKAGE_FFMPEG_FFPROBE=y
+BR2_PACKAGE_FFMPEG_AVRESAMPLE=y
+BR2_PACKAGE_FFMPEG_POSTPROC=y
 BR2_PACKAGE_MPG123=y
 BR2_PACKAGE_VORBIS_TOOLS=y
 BR2_PACKAGE_BZIP2=y