Merge pull request #2 from applyhhj/master

add new module
fixing some errors
Merge remote-tracking branch 'origin/master'
fixing some errors
fixing range sensors
fixing some errors
fixing range sensors
fixing some errors
fixing some errors
fixing some errors
fixing range sensors
fixing range sensors
fixing range sensors
fixing range sensors
fixing range sensors
Merge pull request #3 from applyhhj/master

improve the local planner and add global planner
fixing some pom errors
fixing some pom errors
fixing some pom errors
fixing some pom errors