Refactor
Implement --log-json to write data in JSON format
Decouple Git repository from paths analysed
Ensure that the directories to be analysed exist in the current revision
Resurrect --progress option
Revert "Implement --log-json to write data in JSON format"

This reverts commit 6757aaff11ce340e1d8bca1dd891d61659fae814.
Revert "Refactor"

This reverts commit 034cc8f2fa926c5d36f7961e0fcf923b39d637ac.