[23088] Bug #699686 - Startup dialog windows should be top level windows

Author: Simon Arlott <bugzilla.gnome.simon@arlott.org>

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/branches/2.4@23089 57a11ea4-9604-0410-9ed3-97b8803252fd