pwn_tracker: now closes
Merge branch 'master' of https://github.com/grisetti/g2o_frontend
pwn: now closes
pwn_tracker, cleaning closures
Pwn tracker:
- adjusted caches that now can be shared between closer and tracker
- modified the PwnTrackerFrame structure to hold a temporary for the cloud
- made a small example of an on-the-fly SLAM system that integrates
  - tracker
  - closer
  - caches

Refactoring will be fun....