Change interface for pathfinder method

Add param to handle toggle return value types (path, directions, or
both)
Add another placeholder topic
Various refactorings and bug fixes

- Add convertToMotion helper
- Call sense method in measurementProb method
- Update sense method
- Move getPostion inside Particle filter
- Delete debugging functions
- Use get data to get y,x values of particles as ints to work with json
module
Add various additions

- Use new pathfinder method
- Add locate updateparticles method
- Add mock sense method
- Add new requirements for robosim
- Other changes