* Empty destructors are replaced with default destructors
* A few loop variables made into const references to avoid copies
* Add missing `override` spec for some `Command::execute` methods
* Fixes#925
* Add 'flatten' option to CLI ls command
* Add test for Group::hierarchy() and man page for ls --flatten
* Rename group sort test to align with others
This PR cleans up the `Command` classes in the CLI, introducing a
`DatabaseCommand` class for the commands operating on a database,
and a `getCommandLineParser` command to centralize the arguments
parsing and validation.
The opening of the database based on the CLI arguments and options
is now centralized in `DatabaseCommand.execute`, making it easy to
add new database opening features (like YubiKey support for the CLI).
Also a couple of bugs fixed:
* `Create` was still using `stdout` for some error messages.
* `Diceware` and `Generate` were not validating that the word count was an integer.
* `Diceware` was also using `stdout` for some error messages.
The CLI module was lacking unit test coverage and showed some severe
coding style violations, which this patch addresses.
In addition, all uses of qCritical() with untranslatble raw char*
sequences were removed in favor of proper locale strings. These are
written to STDERR through QTextStreams and support output
redirection for testing purposes. With this change, error messages don't
depend on the global Qt logging settings and targets anymore and go
directly to the terminal or into a file if needed.
This patch also fixes a bug discovered during unit test development,
where the extract command would just dump the raw XML contents without
decrypting embedded Salsa20-protected values first, making the XML
export mostly useless, since passwords are scrambled.
Lastly, all CLI commands received a dedicated -h/--help option.
