Improved UvA detector and tracker

Improvements in UvA detector and tracker:

- use dynamic background model
- use multiple cameras for single detections process
- get appearance informaion from each detection
- kalman filter on position and appearance information
- create entry-exit areas to indicate where humans enter and leave the environment
- map robot position to closest track
- map face recognition of closest track
- multi-threaded detection so more frames can be used