session: more error handling
session: more error handling

Change-Id: I29408bd9fb76e2fa7c2b299126b9d7e1fe8c53d1
Reviewed-on: http://gerrit.aldebaran.lan:8080/2842
Reviewed-by: proullon <ffff9135679d397f48dd743107119b1f6fc32d3d@aldebaran-robotics.com>
Reviewed-by: cgestes <ddb78fe00abb42f91254c16a0860e38eb0781789@aldebaran-robotics.com>
Tested-by: cgestes <ddb78fe00abb42f91254c16a0860e38eb0781789@aldebaran-robotics.com>

aldebaran/libqi,vbarbaresi/libqi,aldebaran/libqi,aldebaran/libqi-java,aldebaran/libqi-java,aldebaran/libqi-java,aldebaran/libqi,bsautron/libqi