CLI flag clean-up
Fixed missing usage information and harmonised the shorthand and long flag names.
Certificate output tweak
Changed the certificate output by adding grouping to subject and validation period as well as improvement to the coloring of the changes.
New flag for the neat output
The vertical indent helper guide lines can now be omitted in the output by using the respective flag.
Internal code improvements
Clean-up of test cases and unification of styles within the test cases. Code refactoring of the path code, which was moved into its own source file for readability.