Fix multi-threading send message though libevent
Fix multi-threading send message though libevent

Change-Id: I2faa6e6c6f3bf8a08e43fc3972a762562bbbde92
Reviewed-on: http://gerrit.aldebaran.lan:8080/2480
Reviewed-by: cgestes <ddb78fe00abb42f91254c16a0860e38eb0781789@aldebaran-robotics.com>
Tested-by: cgestes <ddb78fe00abb42f91254c16a0860e38eb0781789@aldebaran-robotics.com>

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