gtkmountoperation: Add TCRYPT options to the ask-password dialog
Add widgets to the GTK ask-password dialog to allow the user specifying the TCRYPT options now supported in glib.
This requires glib version 2.57.2.
Commit 5d68dab0 improves the appearance of the ask-password dialog to go better with the new widgets.
Corresponding gtk 3.24 merge request: !262 (merged)