Delete message from the map once read.
Delete message from the map once read.

Change-Id: Ie6479499022b986eab2b9899e67a72d6058ff89d
Reviewed-on: http://gerrit.aldebaran.lan:8080/307
Reviewed-by: Cedric GESTES <ddb78fe00abb42f91254c16a0860e38eb0781789@aldebaran-robotics.com>
Tested-by: Cedric GESTES <ddb78fe00abb42f91254c16a0860e38eb0781789@aldebaran-robotics.com>

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