It's strange to be able to close these windows while there is work
in progress.
Also set Qt::WA_DeleteOnClose on both windows to make sure that they
are deleted eventually, no matter what happens.
Adds a `-version` or `--version` option to print just the version
of the program for bitcoind, bitcoin-cli and bitcoin-qt.
Also make it that `-help` can be used to display the help (as well as
existing `--help`). Up to now, `-help` was the only option that didn't
work with either one or two dashes.
- adds a nice and well formated dialog, which displays our -? help message
(all options/paramaters)
- moves aboutdialog.cpp/h to the new utilitydialog
- move GUI shutdown window to utilitydialog
