Bug fix and tidy of EdgeEfficency.

In pyEudetAnalysisOnly.py:
- better save names for plots
- save plot of the total track distribution per edge
- write all 'per edge' plots into root file

In ToolBox.py:
- bug fix: edge_tracks[i] were being filled with only matched tracks. Fixed to fill all tracks.
- better variable names
- return edge_tracks