qt5cinex: Add new Qt5CinematicExperience package.

qt5cinex: Add new Qt5CinematicExperience package.

[Thomas:
 - Change the dependency logic in the Config.in file. We don't want to
   have a 'depends on BR2_PACKAGE_QT5GRAPHICALEFFECTS': it should be
   selected automatically. Instead, let's have a dependency on Qt5 and
   OpenGL, and select everything else automatically. A comment is
   added, shown only when Qt5 is available, on the right platforms
   (which have JSCore support), to explain that we need an OpenGL
   backend.
 - Change the prompt of the package to be qt5cinex, to match the
   package name.
 - Replace "High-definition support" by "High-definition version".
 - Fix a typo in the Config.in help text: definifition -> definition.
 - Add a comment in the .mk file explaining why we install a wrapper
   shell script (explanation taken from Pierre's e-mail).
 - Fix indentation in the install target commands.
 - Keep only sha256 hashes, those are sufficient. Replace the comment
   in the hash file by the more traditional "Locally computed".]

Signed-off-by: Pierre Le Magourou <pierre.lemagourou@openwide.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>