Fix confirmation dialogs for OMEMO and OpenPGP plugin, fix TicTacToe plugin
This fixes confirmation dialogs for OMEMO and OpenPGP where there was no .show()
called.
Additionally, this replaces a leftover NonModalConfirmationDialog
in the TicTacToe plugin. This plugin also got the new SettingsDialog to set board size, a code cleanup, and a malformed JID fix.