Frontend: Page editing: Make sure that thumbnails are correctly updated

Signed-off-by: Jerome Flesch <jflesch@gmail.com>
Backend: make sure that ~/.config exists

Signed-off-by: Jerome Flesch <jflesch@gmail.com>
Frontend: Make sure SIGINT and SIGTERM are nicely handled

Signed-off-by: Jerome Flesch <jflesch@gmail.com>
Frontend: Make sure Gtk.main_quit() is called if there is an exception raised during init

Signed-off-by: Jerome Flesch <jflesch@gmail.com>
Revert "Frontend: Make sure Gtk.main_quit() is called if there is an exception raised during init"

This reverts commit f1bc73dce7850a3eadb5a0f2a7f1150051043240.

That was stupid.
Frontend: About Dialog: Load the paperwork logo correctly

Signed-off-by: Jerome Flesch <jflesch@gmail.com>
Main window: Make sure the main window icon is correctly loaded

Signed-off-by: Jerome Flesch <jflesch@gmail.com>
Merge branch 'testing' into unstable