This commit adds a new `Auth/PasswordCommand` option
to support security best practices re: handling secrets
in CLI program configuration.
Prior to this commit, the two available options
for specifying a password were:
1. via the `Auth/Password` config parameter, or
2. via a `$CALCURSE_CALDAV_PASSWORD` environment variable.
The former is unsafe for obvious reasons;
the latter is unsafe because as long as the script is running,
its environment can be accessed via
$ cat /proc/<pid>/environ
and is thus visible to anyone with access to the system.
This commit preserves preexisting behavior (for backward compatibility)
but removes all mention of option 2 from the README.
Since the README example for option 2 used a password command anyway,
there is little reason to continue its use,
and this commit recommends it be deprecated.
Signed-off-by: Lukas Fleischer <lfleischer@calcurse.org>
e772c4b6d5