Added mutex lock when acquiring point clouds in ground_based_people_detection app.
Updating boost version to 1.53
Testing multicore compiling on travis ci
Removing master branch checkout from travis.yml
Update .travis.yml
Testing multicore compiling on travis ci
Merge pull request #93 from mmunaro/master

Added mutex lock when acquiring point clouds in ground_based_people_detection app and in tutorial.
Merge remote-tracking branch 'pcl/master'