Initial commit of a port of GCompris to QtQuick

- Initial core with:
  - menu bar
  - dialog boxes
  - left menu

- A leftright activity
First implementation of an ActivityInfo in C++
improved ActivityInfo and menu list.
Added resource files in .qrc.
Added files in .qrc, improved menu management.
Better file organization.
Removed a directory level in activity resource.
Removed a directory level in core resource.
better startup sequence.
removed boarddir in activity.
better layout, no more scaling.
remove qtcreator user file.
better layout, fixed path to resources.
added missing resource file for leftright.
renamed application gcompris-qt in GCompris.
android manifest and icon.
improved version based on the weatherapp example.

now the resource file is generated by the .pro file.
use a top level Window instead of Item.
Architecture change, less reliance on core.js
properly destroy the last loaded activity.

properly handle click events on dialogs.
removed core.js. added signals.