QTextStream uses the system default locale, but this breaks in
various situations: (1) It does not work on the native Windows shell
(cmd.exe, Powershell), since the default Windows locale is Windows-1252,
but the shell uses Windows-850. (2) It also breaks on *nix systems where
the locale is Latin1 or C, which is the case for most CI systems or
build servers.
We allow overriding the detected codec by setting the ENCODING_OVERRIDE
environment variable, but otherwise prefer Windows-850 on Windows and
UTF-8 on any other system, even if LANG is set to something else.
This resolves#2413
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.
