Merge pull request #23 from mlosch/master

increase p for breaking. Decrease velocity. Send stop message
Merge pull request #24 from mlosch/master

Merge with diegos changes
Remove wall follower from launch file

Node doesn't exist anymore
Change sign of rotation
wall_following_controller working good enough inside the maze. Created a parameter used as threshold to detect when there is no wall to one side of the robot
flag for msg send, so only one msg is sent