AMB (automotive-message-broker): allow building with Qt5

AMB (automotive-message-broker): allow building with Qt5

v2: (Tadao Tanikawa)
- The recipe in meta-agl-demo which added by Change 4339
  has been merged into this patch.

- The recipe splitted automotive-message-broker_git.bb and
  automotive-message-broker_git.inc.

- Dependencies to gpsd, qtbase and qtdeclarative has been defined
  into PACKAGECONFIG because they need each of their options into
  EXTRA_OECMAKE.

NOTE: Once this patch merged, Change 4339 should be reverted.

v1: (Manuel Bachmann)
We want to be able to build AMB with or without meta-qt5 ;
this is possible by checking the layer presence (see
http://lists.openembedded.org/pipermail/openembedded-devel
/2015-October/103781.html for an upstream OE example).

Enable QtMainLoop and QtQuick/QML plugins, only if meta-qt5
has been added in bblayers.conf.

We need to precise package contents for Bitbake because
the install tree uses a complicated layout.

Change-Id: Ie7e5b6955c76324fd92662fee9caa5bad4dfd2f6
Signed-off-by: Manuel Bachmann <mbc@iot.bzh>
Signed-off-by: Tadao Tanikawa <tanikawa.tadao@jp.panasonic.com>