pinentry: minor annoyances with --help

[Peter Eisentraut]

This is concerning pinentry 0.7.1.  For some reason, the output of 
pinentry-foo --help goes to stderr, not stdout.  This is inconsistent 
with just about every other program out there.  (Try ls, gpg.)  If you 
think about it, if I request help, printing the help information is not 
an error.

Also, I sometimes get this, but only with the Qt version:

$ pinentry-qt --version/--help
Xlib:  extension "GLX" missing on display ":0.0".
Xlib:  extension "GLX" missing on display ":0.0".
[real information follows...]

I think it should be possible to get clean help output without having a 
properly(?) configured X, so maybe the initialization of the Xlib stuff 
can be moved somewhere after the help handling code.

Thanks.