Update commit detection system to handle ambiguous commits

It's possible in Git to create multiple, distinct commits with the same tree content with `git cherry-pick`. See here:
```
sahan@sahan-Lenovo-YOGA-C930-ubuntu:concept$ gloga
*-. b968625 (HEAD -> master) Useless merge
|\ \
| | * 888d690 Secondo commit
| * | f4cb2e3 Secondo commit
| |/
* / f8dc175 Secondo commit
|/
* e809c7f Initial commit
```
In these cases, we would like to have a system to keep track of commits, perhaps by keeping track of the commit times.