initial commit for neutrino-mp yocto layer

This contains:
* neutrino-mp related recipes (in recipes-neutrino): neutrino-mp,
  libstb-hal, libdvbsi++
* neutrino's dependencies (in recipes-local): giflib,
  libjpeg-turbo, lua, libopenthreads, ffmpeg
* right now some board specific stuff for raspberry pi to fix
  up broken meta-raspberrypi (in recipes-raspi)
* rules for neutrino-image (in recipes-images)
layer.conf: add recipes-raspi to BBMASK on non-raspi machines
layer.conf: fix raspi mesa bbmask
ffmpeg: build without theora and vorbis on coolstream
lua5.2: remove readline dependency
curl: build without gnutls/openssl
neutrino: add timezone.xml and init script to package
neutrino-image: tuning

add procps and strace to the image,
increase rootfs size (only effective for USB images)
ffmpeg: add tripledragon config

select ffmpeg instead of libav on all platforms
curl: use 'small' config on Tripledragon, too
libstb-hal: add tripledragon config
neutrino: add tripledragon config, rearrange CFLAGS
neutrino: depend on td-dvb-wrapper module on triple
customize /etc/issue

add bbappend for base-files to add a customized issue and issue.net
add customized busybox config

* add telnetd (yes! telnetd) and matching init script
* change inetd.conf to start busybox ftpd
* add a bunch of other useful tools
* remove dhcpd
add image-config package

* disable bootlogd
* recommend busybox-ftpd
* require busybox-telnetd and busybox-inetd
add feed config for neutrino image

Set your server root (where tmp/deploy/ipk directory is available)
with the IPK_FEED_SERVER variable in conf/local.conf
This should be doable with plain yocto throug IPK_FEED_URIS, but that
does not seem to work.
neutrino: improve init script
neutrino: split off configure switches into neutrino.inc
add a recipe for locally building neutrino-mp

this allows to build just the binary with no packaging etc.