Fixed compilation errors under gcc.
Fixed compilation errors under gcc.

chrisdembia/simbody,simbody/simbody,elkingtonmcb/simbody,chrisdembia/simbody,scamille/simbody,Gjacquenot/simbody,simbody/simbody,Gjacquenot/simbody,Gjacquenot/simbody,elen4/simbody,elkingtonmcb/simbody,elen4/simbody,robojukie/simbody,elkingtonmcb/simbody,robojukie/simbody,scamille/simbody,chrisdembia/simbody,scamille/simbody,robojukie/simbody