Added a reset button. Zoom reset works, but new commits enter directly at their position, when old commits nicely move back to their original position. Need to make the new commits enter somewhere else may be. Or add them one by one ?

The commit click does not work anymore for the commits that were present in the zoomed commits.
De-zooming now works quite nicely.
Modified style. Added a padding distance between commits. Now I have to implement scrolling/panning. Either by moving commits or moving a view box (better choose the latter i guess).
Managed to create a mouse wheel panning. Not very fluid, but working.
Formatted json datafile in playground
Formatted playground data file. Added an info line to each commit. Just need to add date and committer at the end of the line.
Added informations in front of each commit (short sha1, commit message, author name and formatted date).
Also added an highlighting of the commit line when mouse passes over it.