automatic calculation of threshold finished

- calibration needed
- binary closing and opening ops. fix needed
- last mentioned operations are throwing errors
Merge branch 'master' of github.com:mjirik/liver-surgery
Merge branch 'master' of github.com:mjirik/liver-surgery
Major update for uiThreshold.

File uiBinaryClosingAndOpening deleted, function moved to uiThreshold.
Auto-find of threshold still needs to be made better.