Add new lane in lane view should act immediately
Right now, when you are viewing gel image in tab "Lanes", it is easy to make program crash as the lane is not added immediately. Namely, after clicking "Add lane", toolbar button goes into pressed state and user is expected to position the lane by mouse. This has few issues:
- user may not even know they have to position the lane and go to the image
- user can go and open another image/gel and then navigate back to the Lane tab to find out that (s)he has a lane already. Interacting with that lane would make application crash
To avoid these issues, we would have to position the lane as soon as "Add lane" is pressed. Position can be guessed reasonably well by following some logic, subject of discussions.