BUG: Don't nuke external settings changes

Update CTK to include recently added ctkSettingsDialog::reloadSettings
method. Use this to force a reload of settings prior to showing the
settings dialog. This is required in order for the dialog to show
changes that have been made externally (e.g. by installing extensions)
and, more importantly, to avoid overwriting the same when closing (even
canceling!) the dialog.

Issue #3658