Added -u option to use name property of position models as its namespace instead of "robot_0", "robot_1", etc.
Updated topurg model from "laser" to "ranger"
Debug message removed
Update stageros.cpp

Fix if-else format and indentation
C-style casts replaced for C++ style ones
Merge pull request #7 from gustavovelascoh/master

New namespace option and .world file updated.