RELEASE 0.21
build, added missing audioengine plugin
remove sizeTable from Particles

I suspect this to make GCompris crash on some Android devices with the error:
qsgsimplematerial.h:58 (void QSGSimpleMaterialShader<State>::initialize()
[with State = TabledMaterialData]): QSGSimpleMaterialShader does not implement
'uniform highp mat4 qt_Matrix;' in its vertex shader
cmake install, add gstreamer plugins in the linux bundle
pending activity menu cleanup
bundle linux, added a startup script that sets the lib path

with this the linux bundle created with cpack can be started.